Tag Archives: Tenjiku Shogi

Ancient Shogi Revival, Part II: The Big Ones

Since my previous post on our addition of multiple variants of Shogi to the Ai Ai general game-playing software, Stephen and I have been hard at work implementing even more ancient Shogi games.  If you thought the giant 15×15 Dai Shogi was over-the-top, you’ll be amazed what we’ve brought to you this time!

Before I show off what we’ve done, a few points to keep in mind when you download the new Ai Ai version with all these amazing games:

  1. We’ve done a huge amount of work in a relatively short period of time, and have done everything we can to catch mistakes and bugs, but some bugs will still be present!  If you find a bug or incorrect piece movement or something, please do point it out to us, and we’ll do our best to resolve the problem.  Also, some rules are still not quite there (repetition rules, for one), so please be patient.
  2. The AI is very much a work in progress!  Some of these games are truly gigantic, and as a result getting strong play out of the Shogi engine in Ai Ai is really, really difficult.  When you do play against the AI, be sure to give it plenty of thinking time; at an absolute minimum, give it 30 seconds per move for the 16×16/17×17 games, 1 minute for 19×19, and 2 minutes or more for 25×25.  If you have an old computer with a slow CPU you may need to amp those times up significantly.  If the thinking times are too low, you may find the AI repeats moves a lot as it struggles to find useful continuations.
  3. For those games which have a playing community and multiple possible rulesets (Tenjiku Shogi), we have not attempted to resolve any long-standing rules disputes, but instead have opted for being comprehensive.  All the games have options to choose different rules interpretations, piece movements, etc.  Essentially I decided to include a rule proposal or piece movement when that interpretation had been played before, and/or had some historical plausibility, and tried to remain neutral on the long-standing rules disputes in some of these games.  The hope is that players may try all these different variations in Ai Ai, and hopefully use those experiences to choose the best ruleset to play as a community.

With that out of the way, let’s get to the games!  For each one I’ve included some details about the options available to players in Ai Ai.  At the end of the article there is an FAQ section, so please check that for some additional useful tips and tricks for using Ai Ai, and some general questions about our Shogi implementations.

Tenjiku Shogi (16×16)

Tenjiku Shogi (天竺大将棋, or Tenjiku Dai Shogi in Japanese) is a remarkable historical Shogi variant that is one of the most popular of these ancient games among modern players (alongside Chu and Dai Shogi).  Tenjiku Shogi is played on a 16×16 board with each player starting with an army of 78 pieces of 36 different types.  The game stands out not only among Shogi variants, but among Chess-like games in general for its extreme tactical sharpness and super-powered pieces.  The word ‘Tenjiku’ means ‘Indian’ but is more often translated as ‘exotic’, because at the time of Tenjiku’s invention (sometime in the 16th-17th century, most likely), India was seen as a mystical and exotic place, the birthplace of Buddhism and the home of marvellous creatures like tigers and elephants.  Tenjiku certainly lives up to its name, and has some very unique pieces that give the game a distinctive flavour:

  1. Fire Demon — for a start, this incredibly powerful piece is very mobile; it can slide unlimited squares in six directions, or take three successive King-like steps in any direction to dodge around obstructions.  But much more notable is its ability to burn opposing pieces — when the Fire Demon ends its move, all adjacent enemy pieces are immediately removed from play.  This means the Fire Demon may kill up to eight pieces in a single turn (one on its destination square, and seven in the surrounding squares).  This ability even functions on the opponent’s turn; any enemy piece that ends its move next to your Fire Demon is immediately burned and removed from play, and that doesn’t count as your turn!  If your opponent lands their Fire Demon next to yours, their Fire Demon is burned, and it doesn’t get to burn any of your pieces before it is removed from the board.  Fire Demons can still be captured by any piece that lands directly on its square.
  2. Range-Jumping Generals — Four pieces in Tenjiku, the Great General, Vice General, Rook General, and Bishop General, have the ability to make range-jumping captures, where they may leap over any number of friendly or opposing pieces to land on an enemy piece and capture it.  To keep this amazing ability under control, these pieces are subject to a hierarchy, and may not jump over pieces above them in that hierarchy; this allows players to block these powerful jumps with careful defensive placement.  In the two main Tenjiku rulesets there are two different interpretations of this ability; more on that in the discussion of game options below.
  3. More powerful Lion pieces — Tenjiku includes all the pieces present in Chu Shogi including the remarkable Lion, which may move and capture twice in a turn.  In Tenjiku the Lion can promote to an even more powerful piece, the Lion Hawk, which may move as a Lion or a Bishop.  Tenjiku also includes the Free Eagle, a piece that may slide an unlimited number of squares in any direction, or may make a Lion-like double-move but only diagonally.

Combine all these powerful pieces and you get a game that despite its size is remarkably fast-paced and violent, with deadly tactical combinations possible right from the beginning of the game.  Most large Shogi variants have quite long and subtle openings, but in Tenjiku one opening mistake might lead to an embarrassingly early checkmate.  These unusual properties have enabled the game to develop a small but dedicated Western playing community, and as a result numerous resources are available for prospective players, including opening guides.

Rulesets and Options

Tenjiku Shogi has had a lot of attention over the years since it was introduced to the West in the 1980s by George Hodges.  Unfortunately, as with many of these ancient games, some important rules questions remain unresolved.  Modern players have developed two main rulesets that are in use, both of which are available in Ai Ai:

  1. Richard’s PBEM Server ruleset: the yearly Tenjiku Shogi Championship tournament is played on Richard’s PBEM Server, and uses this ruleset.  In brief, the main distinguishing features here are: Fire Demons may slide unlimited squares diagonally or vertically; range-jumping generals may capture Kings or Princes while jumping, allowing for some very early smothered mates to occur; and the Heavenly Tetrarchs do not have a vertical sliding move (and in fact use an odd set of movements that seems to be a mistake, so you may want to use the TSA Tetrarch variant instead).  Early checkmates are very common in this ruleset.
  2. Wikipedia/Chess Variant Pages ruleset: these rules have been promoted by HG Muller, and produce a somewhat less violent Tenjiku experience than the PBEM ruleset.  In this ruleset: Fire Demons may slide unlimited squares diagonally or horizontally; range-jumping generals may not capture Kings or Princes while jumping, eliminating the early smothered mates; and the Heavenly Tetrarchs have a vertical sliding move, making them a clear upgrade over the Chariot Soldiers from which they promote.

Various spirited arguments have taken place, and continue to take place, over these key rule interpretations.  In Ai Ai we have chosen instead to implement both options, to give players a choice of how they want to play — simply load TenjikuShogi(PBEM).mgl for the PBEM ruleset, or TenjikuShogi(WP).mgl for the Wikipedia/Chess Variant Pages rules.  In the hope of helping the community to resolve these rules discussions, we have also included a customisable version (TenjikuShogi(Custom).mgl), which allows players to customise their ruleset with the following options:

  1. Fire Demon move — you may choose whether the Fire Demon slides diagonally and vertically (PBEM version), or diagonally and horizontally (WP version).
  2. Range-Jumping Generals — you may choose whether they can capture the Royal pieces (King and Crown Prince) by jumping (PBEM) or not (WP).
  3. Heavenly Tetrarchs move — you may choose from four (!) different move options for the Heavenly Tetrarchs:
    1. PBEM move — no vertical slide, may never move to the eight adjacent squares, may capture without moving on adjacent squares, adds a three-square vertical jump (which seems like a mistake)
    2. Wikipedia/Chess Variant Pages move — vertical slide, may never move to the eight adjacent squares, may capture without moving on adjacent squares
    3. TSA move — the original move advocated by The Shogi Association — no vertical slide or vertical jump, may never move to the eight adjacent squares, may capture without moving on adjacent squares
    4. Sho Shogi Zushiki move — vertical slide, may never move to the eight adjacent squares, and may NOT capture without moving on the adjacent squares
  4. Lion Hawk move — you may choose two variants of the Lion Hawk:
    1. TSA move — the Lion Hawk does NOT have Lion Power, but instead may move as a Bishop or step twice as a King in any direction, but may only capture once during this two-step ‘area move’
    2. Modern move — the Lion Hawk moves as a Bishop or a Lion, with full Lion Power
  5. Free Eagle move — you may choose two variants of the Free Eagle:
    1. TSA move — the Free Eagle may move as a Free King, or may jump two squares orthogonally
    2. Modern move — the Free Eagle may move as a Free King, or may make two successive one-square diagonal steps, which can include making two captures, capturing an adjacent piece and moving back to the starting square (igui capture), or passing a turn by moving to a diagonally adjacent square then back to its starting point.
  6. Allow Zone-Passing — you may choose whether or not to allow zone-passing; if zone-passing is allowed, that means that Lion-Power pieces may promote if they make a Lion-style move into the promotion zone and immediately back out again on the same turn.
  7. Water Buffalo promotion burn — if Water Buffalo promotion burns are allowed, that means that when a Water Buffalo promotes to Fire Demon, it may immediately burn all adjacent enemy pieces on the move where it promotes.  This is suggested in the Wikipedia/Chess Variant Pages ruleset.

That’s a lot of options!  I’m 100% sure that some members of the Tenjiku community would prefer that I adopted only their preferred ruleset/piece movements, but again I have tried to avoid wading into any long-standing rules disputes here.  I opted to go over all Tenjiku-related materials I have and simply include any rules/movements that have some historical backing, or have been played before, or advocated seriously as a proposed change to the rules, so that players may try them all and make an informed choice.  I did decide not to include the original TSA rules for the range-jumping generals, however, as these have been shown to give an easy win to Sente.

Promotion Rules and 50 Move Rule

Note that I have decided to offer all three main Tenjiku variants with the Chu Shogi promotion rules; this is mainly because there seems to be some momentum lately to adopt these rules in the PBEM Server version, and the Japanese Wikipedia rules state the Chu Shogi promotion rules are applied in this game.  If anyone wishes to use modern Shogi promotion rules instead, simply open the appropriate .mgl file in a text editor, and find a line that looks like this:

“promotionRule” : { “rule” : “ChuShogi”, “allowIguiPromotion”:false },

Remove the “rule” : “ChuShogi”, part and you will be using modern Shogi promotion rules.

I also decided not to include any equivalent to the 50-move rule in Chess, mainly because these rules are a modern invention and definitely not part of ancient Shogi, and also because we have no idea what a good move threshold would be in these huge games.  However, if the community does want to use a 50-move rule equivalent, this can be added to any Shogi variant by opening the appropriate .mgl file, finding the section called “endCondition”, and within the square brackets adding another line that looks like this:

{ “condition”:”boredom”, “who”:”all”, “result”:”draw”, “moves”:50 },

Simply change the move number to your preferred option, and that’s it!

In any case, I’m a strong believer that debating game rules without playtesting them is pretty pointless, so I’m hoping that having all these options available will help the various rules debates to eventually get resolved.  With these different rules variations now playable online as well as against the AI, players may thoroughly test them and decide together how they want to play Tenjiku in the modern age.

Tenjiku Sub-Variants

For players who are interested in playing Tenjiku but find the full-sized game intimidating, we’ve also included two smaller modern variants of Tenjiku Shogi:

Nutty Shogi (13×13)

Nutty Shogi was invented by HG Muller in 2015, and is a very enjoyable reduction of Tenjiku Shogi to a more compact 13×13 board.  All rules remain the same, so it’s a straight subset of the full game.  In this implementation players may choose from the options present in the custom Tenjiku Shogi version, in order to match their preferred ruleset for the larger game.   Note that the game seems to have been designed to use the Wikipedia/CVP rules, so I recommend using those options.

Makyou Shogi (12×12)

I’m a fan of Nutty Shogi, but find it mildly inconvenient in that no historical Shogi variants use a 13×13 board, so it’s not easy to play physically even with my collection of Shogi variant pieces and boards.  So I created Makyou Shogi, a reduced version of Tenjiku designed to fit on a 12×12 Chu Shogi board.  Makyou is a Japanese word meaning ‘demon-infested place’, which felt appropriate for this tight board packed with powerful pieces!  Note that the piece mix is a bit different from Nutty Shogi.  Also, this game is still being tested, so the starting array may change over time.

Makyou Shogi allows players to tweak any of the rules/piece options present in the Tenjiku Shogi customisable implementation; having said that, I strongly recommend using the Wikipedia/CVP rules in this game, as the PBEM pieces make the game too tactical with little room for strategy.

Dai Dai Shogi (17×17)

With Dai Dai Shogi, we enter the realm of the truly gigantic Shogi variants.  Players start the game on this huge 17×17 board with 96 pieces each of 64 different types (4 additional types appear only via promotion).  Among those pieces are the ultra-powerful hook-moving pieces — the Tengu and the Hook-Mover — which may make two successive moves as a Bishop or a Rook respectively, making a right-angle turn after the first one (but may only capture once).

Dai Dai Shogi is the smallest of the ancient Shogi games to use a promotion-by-capture rule.  Instead of promoting upon reaching the enemy camp, pieces in Dai Dai Shogi promote immediately after they capture any opposing piece (if the piece has Lion Power, the promotion happens at the end of their complete move).  Promotion by capture is mandatory and cannot be deferred.  Unusually for a Shogi variant, most pieces in Dai Dai Shogi do not promote, including Pawns; this relative lack of promotable pieces together with the promotion-by-capture rule gives the game a quite different feel from the other historical Shogi variants.  The promotion-by-capture rule has a profound impact on tactics, too, as players must now be careful that any capture exchanges don’t leave the opponent a strong promotion at the end of the fight.

The Dai Dai Shogi starting array is packed with pieces and very asymmetric, with many pieces only appearing once rather than in pairs.  The initial position is also arranged quite differently from the other large Shogi variants (with the exception of Tai Shogi, to an extent) — the strongest pieces are at the back of the player’s army, rather than the front. This means opening play is quite slow and subtle, as players try to develop their pieces soundly without leaving any easy captures for the opponent to use for promotion, while also trying to free their most powerful pieces.  The endgame can become pretty hectic, as the hook-moving pieces finally come out to play and their incredible mobility makes them a deadly threat.  All told the game is thoroughly engrossing, deeply strategic and yet filled with rich tactics:

”This is the writer’s personal favourite of the [large Shogi variants], owing to the tremendous variety of pieces, the wealth of strong pieces and weak pieces with strong promotions, and the asymmetrical opening setup…. What often happens in practice is that the entire board opens up into the most complex tactical struggle seen in any of the forms of Shogi.” (R. Wayne Schmittberger, writing in Shogi Magazine in 1981)

Rulesets and Options

Fortunately, unlike Tenjiku Shogi there are relatively few major rules disputes in Dai Dai Shogi, if only because very few people have played it.  As a result our implementation has just two main incarnations: one which includes the troublesome Great Elephant piece in four variations (DaiDaiShogi(complete).mgl); and another which excludes the Great Elephant piece entirely, which apparently is the case in two historical sources (DaiDaiShogi(noGE).mgl).  In both versions the player may choose between two variations of the Furious Fiend’s move, as well.

Alongside the Elephant variants described in the translation notes article, in this final version we also included a variant move sometimes used in Tai Shogi,  which allows the Great Elephant to  move as a Lion Dog or slide up to 5 squares horizontally or diagonally backward.  This move is recommended by the Japanese Chu Shogi Association (Chu Shogi Renmei).

Sub-Variant: Cashew Shogi

Invented by HG Muller in 2015, Cashew Shogi is a reduction of Dai Dai Shogi onto a smaller 13×13 board.  This variant includes most of the characteristic pieces of the larger game, but substantially reduces the number of moves one has to remember.  Despite the size reduction, the AI vs AI test games I’ve tried are often not that much shorter than the full-sized games of Dai Dai Shogi, and sometimes are substantially longer!  I suspect this is mostly due to the size difference, however; the much larger board size in Dai Dai Shogi gives the AI a hard time, so it tends to make more serious blunders during play.  In Cashew Shogi the AI can find stronger moves, and is less likely to blunder its way into a quicker loss.

Our Cashew Shogi implementation allows players to choose their preferred form of the Great Elephant and Furious Fiend, as in Dai Dai Shogi.

Maka Dai Dai Shogi (19×19)

Let’s get my biases out there straight away — Maka Dai Dai Shogi is a very cool game, and I’m overjoyed that it’s now playable in Ai Ai.  This is a truly immense game, played on a 19×19 board with 96 pieces of 50 types in each player’s starting army, and it uses a promotion-by-capture rule like Dai Dai Shogi (more on this below).  What makes Maka Dai Dai Shogi stand out is the presence of several unique mechanics and pieces that give this enormous game the feel of a giant mythical battle; this is no coincidence, as the game is clearly heavily influenced by Buddhist mythology:

  1. The All-Powerful Emperor — unlike the other Shogi games, in Maka Dai Dai the King can promote!  If your King captures an enemy piece, he may promote to Emperor, perhaps the most powerful piece in any Chess-like game.  The Emperor can instantly jump to any square on the board, including squares occupied by enemy pieces, but it may not enter protected squares or capture a protected enemy piece.  Checkmating the Emperor seems impossible, but the hook-moving pieces can make it happen.
  2. The Deva/Dark Spirit/Teaching King/Buddhist Spirit — At the start of the game the Kings are flanked by a Deva and a Buddhist Spirit, two incredibly weak pieces with very awkward asymmetric 1-square moves.  But when a Deva captures an enemy piece, it becomes a Teaching King, a super-powered piece that may move as a Lion Dog or a Free King; likewise, the Dark Spirit becomes a Buddhist Spirit, which moves as a Lion or a Free King.  More intriguingly, these pieces are contagious — that means that if an enemy piece captures your Deva or your Teaching King, it immediately becomes a Teaching King, or if it captures your Dark Spirit or Buddhist Spirit it immediately becomes a Buddhist Spirit.  Consequently these pieces are very difficult to eliminate from the board permanently, unless they are taken by another Teaching King/Buddhist Spirit or by a royal piece (King, Emperor or Prince, who ignore the contagious aspect and simply promote normally).  Some Shogi historians believe the Buddhist Spirit and Teaching King may represent the Buddha and the Lotus Sutra, respectively.
  3. Promotion by Capture — as in Dai Dai Shogi, pieces in Maka Dai Dai Shogi promote when they capture something, so there are no promotion zones (or, alternatively, we can consider the entire board the promotion zone).  However, there are two variants of this rule: in one version, suggested by Wikipedia and the Chess Variant Pages, the capturer may choose whether to promote or not, unless the captured piece is promoted, in which case they must promote; in the other, suggested by the TSA rules pamphlet and Japanese Wikipedia, pieces must promote when they capture, as in Dai Dai Shogi.  In either case, Maka Dai Dai moves away from the Dai Dai Shogi model and allows nearly all pieces to promote, more like the other historical variants.  Many short-range pieces promote to ‘Free’ versions of themselves, which move in the same directions but extend all one-step moves into unlimited sliding moves.

These elements combined give Maka Dai Dai Shogi the strategic depth and nuance of the other large games, but punctuated with moments of extreme dynamism: the Emperor can teleport around the board savaging his enemies; the two powerful, mystical spirits stalk the board and never stop hounding one player or the other; and even the weakest pieces can promote into powerful board-spanning threats.  I honestly can’t recommend this game enough, it’s huge and crazy but very very interesting and enjoyable to play, and just packed full of cool pieces.  Here are my picks for the top ten coolest pieces in Maka Dai Dai Shogi, from strongest (Emperor) to weakest (Free Bear):

Fortunately, it seems I’m not the only one who developed a bit of an obsession with this game.  In the historical documents there is a long chant given that helps players to remember the opening setup, which suggests the game was popular enough that players developed these kind of mnemonics to help them get the game started more quickly.  A research group in Osaka, led by Professor Tomoyuki Takami, has been studying this game for years, generating a lot of lively debate about its origins, influences and rules; Professor Takami has also invested a lot of effort in promoting the game.  I have a fervent hope that one day these pockets of interest in Maka Dai Dai Shogi will blossom into a full-blown playing community, and this Ai Ai implementation is my attempt to help that process along.

As a side note, Prof Takami’s group has developed a set of rules for what they believe to be an earlier form of Maka Dai Dai Shogi, which they call Maka Dai Shogi.  This game also seems very interesting, but we haven’t included this in Ai Ai because it would involve programming numerous variant rules and pieces, and the rules are not stable and seem to change fairly frequently as Prof Takami finds new evidence in the historical documents.  At some point we may include it, when I have time to reach out to Prof Takami and get a comprehensive set of rules.

Rulesets and Options

Maka Dai Dai Shogi has relatively few options to worry about when starting a game:

  1. Promotion Rule — players may choose whether promotion on a capture is compulsory, or whether it is generally optional but becomes compulsory when the captured piece is promoted.
  2. Furious Fiend move — as in the other large games featuring this piece, players may choose the old TSA Furious Fiend move (Lion + 3-step slide move) or the more current interpretation (Lion + Lion Dog).

That’s it!  Note that the old TSA rules included a variant Teaching King move which was nonsensical, as it had the piece moving like a Free King or using a 3-step slide, which completely overlap.  The one historical Japanese source I have available clearly indicates a Lion Dog move plus Free King move, and all other sources I can find suggest this move, so I’ve opted not to include the TSA move here.

Sub-Variant: Macadamia Shogi (13×13)

Invented by — you guessed it — HG Muller in 2015, this 13×13 reduction of Maka Dai Dai Shogi retains all the most distinctive pieces in the game and removes most of the weaker ones.  The consequence is a quite intense game, where a nerve-wracking opening phase tends to develop into a rather intricate middlegame as the players try to outfox one another with their remaining nimble power-pieces.  I’ve enjoyed my time with this game quite a bit, and definitely recommend trying it.

Our implementation of Macadamia Shogi allows players to select the same options as the main game (promotion rule and Furious Fiend move).

Sub-Variant: Hishigata Shogi (19×19)

Hishigata Shogi was invented by Sean Humby in 2005, and attempts to slim down Maka Dai Dai Shogi in a different way.  In this game the full-size 19×19 board is retained, but the initial position excludes nearly all the weaker pieces, and the King is placed much closer to the centre of the board and surrounded by his army.  The result is an extremely fast-moving game, as the power-pieces swoop dangerously around the board, picking away at the enemy King’s dense pack of protectors until they can find a fatal weakness.

Personally I substantially prefer the original game to this variant; Maka Dai Dai Shogi shines partly because the deadly power-pieces are embedded in vast armies of weak-yet-still-important short-range pieces, balancing out their ridiculous power somewhat thanks to the levelling effect (referred to in my first post on our Ai Ai implementations).  Hishigata abandons much of that, and I feel the result is a bit less nuanced.  However, I can imagine some players will vehemently disagree with me and will enjoy the frenetic tactical explosion this variant offers, so of course I include it here for everyone to try for themselves!

Upon starting a game of Hishigata Shogi players may choose the promotion rule to use, but there is no choice of Furious Fiend moves as that piece doesn’t appear in this game.

Tai Shogi (25×25)

Tai Shogi is a truly immense game, and is the second-largest Chess-like game ever created (36×36 Taikyoku Shogi being the largest).  On its vast board of 625 squares, players battle it out with dense armies of 177 pieces each, with 93 different piece types present in the initial position.  Tai Shogi essentially combines the pieces present in Dai Dai Shogi and Maka Dai Dai Shogi, and adds an additional nine new types of pieces.

Until now I haven’t had the opportunity to play a full game of Tai Shogi, so I’d always seen it as phenomenally impressive, but probably too big to be truly playable.  However, since implementing it in Ai Ai I’ve played with it quite a bit, and I have to say I was wrong; Tai Shogi may be huge, but it’s definitely playable!  Not only that, the sheer size and scale makes the game feel quite epic, and I’ve enjoyed my time with it so far.  For those of you out there who are familiar with Dai Dai Shogi and Maka Dai Dai Shogi, please do give this game a try; the learning curve will be small, since there are only nine new pieces, and you’ll be able to develop some basic strategies based on your experiences with those games.

Tai Shogi has a couple unique properties of note:

  1. No Kings on the board — instead of starting with a King, players in Tai Shogi start with both an Emperor (!) and a Crown Prince on the board, both of which must be captured to win.  Since the Emperor can jump instantly to anywhere on the board, that means it effectively serves as a potential extra protector for every friendly piece, adding an additional tactical wrinkle to any battles taking place.  Games also tend to run long (2,000 moves is a typical length for a game), since the Emperor is far too powerful to get checkmated in the early stages when few pieces are developed and available to attack it.
  2. Full complement of hook-movers — Tai Shogi players have at their disposal the Hook Mover (double Rook), Capricorn (double Bishop), Tengu (double Bishop + single orthogonal step) and Peacock (double Bishop, but only forward).  With six hook-moving pieces on each side of the board, long-distance captures are always a threat, especially later in the game as the board empties out a bit.  However, players must use these pieces cautiously — some will demote on capture, and they can’t be spent carelessly as otherwise checkmating the opposing Emperor will become very difficult!

Playing Tai Shogi is quite an experience, and it’s most definitely the most wargame-like of the many Shogi variants I’ve played so far.  The starting armies are so huge that the board tends to have multiple local skirmishes happening at the same time, and the advancing Pawn lines backed by swarms of generals and mythical beasts reminds one of the clash of phalanxes of ancient soldiers.  The game clearly has scope for incredibly varied strategies, so I’m looking forward to playing more so I can begin to appreciate its subtleties.

Rulesets and Options

Tai Shogi has two main rulesets in use, which substantially change the gameplay:

  1. Japanese Wikipedia rules — These rules essentially combine Dai Dai Shogi and Maka Dai Dai Shogi in their entirety.  Most of the pieces from both games are included, and they promote as they do in their parent games, meaning that nearly all pieces in the game promote.  Promotions are compulsory upon capturing an enemy piece, as in Dai Dai Shogi.
  2. TSA rules — In the TSA version of the game, promotions are limited to about 1/3 of the pieces in the starting array, similar to Dai Dai Shogi (Pawns don’t promote here, either).  Promotions are also compulsory on capture, like Dai Dai Shogi and the Japanese Wikipedia rules.

The additional 60 or so promotions available in (1) make the game feel substantially more hectic than the TSA rules, and since I don’t have the historical sources available to decide on way or the other, I decided to include both rulesets in separate files so that players may choose for themselves.  Ruleset (1) is in TaiShogi(JWP).mgl, and ruleset (2) is in TaiShogi(TSA).mgl.  Try them both and see what you think!

Note that English Wikipedia has yet another set of promotions, but the entire page appears to be in a state of flux and so I don’t consider those suggested promotions reliable enough to include as a third option.  Similarly, the German Chu Shogi Association appears to suggest yet another variant where Crown Princes may promote to Emperors, but I can’t find much support for this idea elsewhere.

Players may also choose between variant piece movements for several pieces:

  1. Great Elephant — this has the same four move options as in Dai Dai Shogi
  2. Furious Fiend — this has the same two variants as in other games including this piece
  3. Fierce Eagle — players may choose between the TSA move given for this piece and the Japanese Wikipedia move
  4. Great Dragon — players may choose between the TSA move and Japanese Wikipedia move

Given the sheer size of this game, I wouldn’t worry too much about which moves you choose; the changes between each option are minor and will have little to no impact on the course of a full game on this massive board, particularly when there are numerous other pieces with substantially more power flying around.

Sub-Variant: Mini Tai Shogi (15×15)

This work-in-progress variant is my own creation, and is an attempt to shrink down the Tai Shogi experience onto a smaller 15×15 board.  The most exciting pieces from Tai Shogi are all present, and players start with Emperors on the board and multiple hook-movers, plus Poisonous Snakes and Old Kites that can promote to hook-moving pieces in the endgame.  My test games thus far have lasted anywhere between 400 and 1,000 moves, so still a long haul but substantially shorter than Tai Shogi.

At the start of the game, players may choose variant moves for the Great Dragon, Furious Fiend and Great Elephant.  Players can also decide to replace the Emperors with Princes, if they want a less mind-bending endgame; however, I strongly recommend using Emperors to get the full Tai Shogi experience!

As with Tai Shogi, there are two versions of Mini Tai Shogi — one following the promotions set out in Japanese Wikipedia, the other following the TSA rules.  The Japanese Wikipedia version has nearly all pieces promoting, while the TSA version has more limited promotions available.

Mini Tai Shogi is definitely a work-in-progress, but so far I’ve found it enjoyable to play.  Tai Shogi is such a huge game that reducing it down to 15×15 means eliminating a huge number of pieces from the board; over time I will experiment with different piece choices and arrangements for Mini Tai, and may even produce a second smaller variant with a very different set of pieces drawn from Tai Shogi.

Emperor Endgame Trainer

Maka Dai Dai Shogi and Tai Shogi add a new endgame twist over the other ancient Shogi games — the mighty Emperor, who can jump instantly to any unprotected square on the board.  At first this piece is very confusing to deal with, and checkmating it can seem almost impossible.  To make the transition to Emperor endgames a bit easier, and to open up a way to have some quick fun with all these crazy Shogi pieces, we added an Emperor Endgame Trainer to Ai Ai that helps you learn how to cope with Emperor endgames.

When you load up the trainer (EmperorEndgameTrainer.mgl), you’ll be given a menu where you may choose five different pieces for Sente to use to try and checkmate Gote, who starts with an Emperor and two Gold Generals.  If you have Ai Ai play as the Emperor side, you can experiment with different piece combinations and learn how you can checkmate in these wild new endgames.

Rulesets and Options

Upon loading the trainer, you will be able to choose five pieces for Sente to use, from the entire current list of available Shogi pieces in Ai Ai.  However, to keep things applicable to the actual games that use the Emperor, only the pieces available in Maka Dai Dai and Tai Shogi can promote, and they use the promotion-by-capture rule.  At the start you may also select whether to have promotion-by-capture as compulsory (like Tai Shogi) or optional (like Maka Dai Dai Shogi).

You may also choose whether one or both sides have a King or an Emperor, if you just would like to gain some experience with some of the Shogi variant pieces in more normal endgame situations.  The board size is configurable too.

Note that if you leave piece selections on ‘Random’, you may occasionally get starting positions where the enemy Emperor/King can be captured immediately; for example, selecting a Bishop hook-mover like a Capricorn, Tengu or Peacock as Sente Piece #2 will cause this.  If that happens, you can click the Game menu and select Game Parameters to choose different pieces and try again.

Shogi-Inspired Chess Variants

For those die-hard Chess players who miss the classic FIDE pieces and those wonderful FIDE Pawns, don’t fret!  I’ve also put together some highly experimental Chess variants that try to capture the large Shogi feel in a distinctly Chess-flavoured package.  These games use Chess pieces and popular fairy pieces, but adopt large Shogi conventions like very dense starting setups, promotions for many other pieces besides Pawns, and eschewing castling in favour of starting the Kings in strong fortresses right from the beginning.

All three games are really just intended for fun, so please don’t take them too seriously; having said that, I have playtested them quite a bit and they’re playable and not obviously broken.  The starting positions have been tweaked and tuned to avoid any obviously weak squares for either side to target in the opening, the piece mixes have been adjusted following test games, and promotions have been swapped around in each game to try and encourage the use of certain pieces.

Rider Romp (10×10)

This game is sort of a bridge between 10×10 Chess variants like Grand Chess and Opulent Chess and the large Shogi experience.  The opening setup is denser than most 10×10 Chess variants, and the pieces are more powerful and many are capable of promotion.  The four middle Pawns have been replaced with Stewards, variant Pawns that can move and attack in four directions, which are quite robust defenders; in early testing, a line of ten normal Pawns proved to be somewhat feeble resistance against the onslaught of all these power-pieces.

The name comes from the game’s theme of promoting one’s pieces to stronger forms that include additional ranging moves.  Some of the promoted pieces are ‘rider’ pieces, a term originating from fairy Chess which means they extend a basic move by allowing the piece to perform it repeatedly.  Nightriders are a classic example — they are Knights that can perform repeated Knight leaps in the same direction in one turn.

Rider Romp starts out fairly tactical, with long-range attacks flying everywhere; just mind the Steward Pawns in the middle four files.  Once the board empties a bit promotion really becomes a focus.  These games use promotion zones like the large Shogi games, so players will have to try to advance their own pieces to achieve strong promotions, while trying to guard their own huge promotion zone against incursions from enemy pieces with high-impact promoted forms.  In my tests a game played out to the bitter end takes about 150-250 moves (using Shogi-style move counting, not Chess style!).

Neutronium Chess (12×12)

Now things get a bit crazier.  Neutronium Chess gets its name from the ridiculously dense material that makes up neutron stars, because this game is absolutely packed to the brim with pieces at the start of the game, and there are 33 distinct piece types available for use.  The piece lineup includes various strong leaping pieces, some with additional orthogonal or diagonal step options to add flexibility, and powerful sliding pieces as well.

My favourite pieces in this game are the Griffon and Manticore, which are bent slider pieces — the Griffon takes one step as a Bishop then can slide unlimited squares outward as a Rook, while the Manticore takes one step as a Rook and then can slide outward as a Bishop.  This gives them some very surprising attack options, but also gives them a fundamental asymmetry; Griffons and Manticores can’t retreat the same way they advanced, so they must be deployed with finesse.   This game (and Dai Chess) also contains other bent pieces, including the Crooked Rook and Crooked Bishop that move in zig-zag patterns, and the Ship (invented by Jean-Louis Cazaux here), a vertical-only Griffon.

As with Rider Romp, many pieces promote in Neutronium Chess, so watch out for strong pieces getting even stronger in the endgame.  In play this game has an unusual feel, with the phases of the game proceeding in a Shogi-like progression, but the high-powered pieces create complex, long-range tactical shots more reminiscent of Chess.  I’m still not sure it’s ‘good’, as such, but I do have a lot of fun playing it.  A typical game lasts anywhere from 200-400 moves; the sample game shown above is on the shorter side, finishing at 261 moves.

Dai Chess (15×15)

Dai Chess takes the next logical step and increases the board size to a massive 15×15.  This game uses the exact same starting squares for pieces as Dai Shogi, but with all different pieces.  All Pawns start the game protected, so there are no immediately obvious weak points to target in the opening.   Players start play with 65 pieces each, and there are a total of 46 piece types available for use.  Given the larger board size I wanted to try for a more strategic feel in this game, so some of the more powerful pieces from Rider Romp and Neutronium (like the Griffon and Manticore) now only appear via promotion, calming the early stages of the game somewhat.  One aspect I’m still working in is the placement of the colourbound pieces, which is troublesome due to the board having odd dimensions rather than even, so keep an eye on that in future revisions.

Dai Chess really amps up the large Shogi feel of this series of variants, not just by using the Dai Shogi position but also by adding more promotions.  Nearly every piece promotes, and in keeping with what we expect from Chess, all promotions are an improvement in strength; I’ve avoided any demotions in the style of Dai Dai/Tai Shogi.  This game makes use of a lot of leapers, so good tactical vision is necessary to avoid early loss of strong pieces.  In the endgame, sliding pieces become dominant as they can promote much more easily, which again is reflective of the large Shogi inspiration.

A typical game of Dai Chess lasts about 400 moves, sometimes substantially more; the sample game above lasted 495 moves.  Ai Ai can actually play this game reasonably competently at 15-30s thinking time, but it can end up being a bit greedy in the opening; if you want a greater challenge, trying playing a cautious, positional opening for Ai Ai before turning the AI on.  Be careful though — for human players all these weird leaping pieces can make it hard for us to spot good moves, but the AI doesn’t have that problem!

Expanded Chess/Get Bent/Symmetric Sissa

If you’d like to experiment with those interesting bent-slider pieces some more, you can also check out my variant called Get Bent, also added to Ai Ai in this release, which includes a whole mess of them on a 10×10 board; it’s a very fast-paced tactical game.  I mainly made it to get familiar with these odd pieces, so it’s just for fun.  Pawns promote to extremely powerful Griffon/Manticore compound pieces, so watch out for that!

We have also included Expanded Chess, a nice variant by Daniel Zacharias which has Griffons and Manticores as well, and Symmetric Sissa, a showcase for the multipath Sissa piece, which on each move must take the same number of steps as a Rook and a Bishop (in either order).

None of these three variants have anything to do with Shogi, but since they’re in the new release I felt it was worth highlighting them anyway!


Next Moves

Sorry for the insanely long post, but as you can see, Stephen and I have done a whole lot of work on these games over the last few months.  As I mentioned at the beginning of this article, bugs will very likely remain in one or several of these games, but we’ve at least reached a stage where the games all function and we’ve incorporated every rule/piece option that seems plausible.

From here, we hope you Shogi fans will give these games a try, let us know how you find them, and maybe organise a tournament or two.  If/when any bugs crop up, please let us know of course!

I’m sure some folks would prefer there were less options to deal with in each game, but honestly I can’t see any other way to go; the alternative would be to decide unilaterally how these games should be played, but the information we have on the historical rules is very fragmented, so I don’t feel qualified to do that.  I also don’t want to take sides on the online debates regarding these rules, which have been going for far longer than I’ve known about these games.  In any case, my hope is that these options can be trimmed over time as the community tests them out and reaches a consensus on what pieces/rules are most enjoyable.  Similarly, as I get my hands on the historical sources I’ll revise things here and there as needed.

After this release we’re taking a little break from Shogi programming, but at some point down the line we do hope to bring in the legendary Taikyoku Shogi as well.  That will take a lot of research on my part, given there seem to be major differences in the rules in each of the three main historical sources, but I look forward to learning more about that massive game along the way.

In the meantime, go play some ancient Shogi, and have fun!


Frequently Asked Questions

“How can I choose a Shogi variant to play?”

On the File menu in Ai Ai, click ‘Choose Game’.  A new screen will open with a file browser on the left and a preview display on the right.  Open the ChessFamily folder on the left, then open the Shogi sub-folder.  Within that you will modern 9×9 Shogi, and two sub-folders, one for Historical variants and another for Modern variants.  Pick your favourite, double-click it and Ai Ai will load it up!

Alternatively, hit Ctrl+Shift+F (Cmd+Shift+F on Mac) and start typing the name of the game, and you should be able to load it that way.

“How can I play online?”

Instead of running ‘ai ai.jar’, run ‘online.jar’ which is included in your Ai Ai folder.  Once it starts up, click the button on the left to create an account, then click the link in the subsequent confirmation email (check your spam folder if you don’t see it).  Once your account is confirmed you can login and start playing!  Ai Ai supports correspondence-style online play.

“I’m playing Tenjiku Shogi, how do I use igui capture with my Heavenly Tetrarchs?”

Click and drag the Tetrarch on top of the adjacent piece you want to eat, and when you let go of the mouse button that piece will be igui captured.

“I can’t visualise these crazy moves!  Can Ai Ai show me where my pieces can go?”

It sure can!  There are three main options for this:

  1. On the ‘Settings’ menu, turn on ‘Show available moves’.  This will highlight any pieces on your side that have available moves on your turn, and if you click and hold on that piece, Ai Ai will show you what squares it can legally reach.
  2. Also on the ‘Settings’ menu, turn on ‘Highlight moves from position’.  When this option is on and you click and hold on one of your pieces, Ai Ai will dim the rest of the board and show you where your piece can move using arrows and will highlight the possible destination squares.
  3. On the ‘Game’ menu, choose ‘Available moves…’ and a window will open up that will show you a visual depiction of every possible move in the current position; you can choose your move by clicking through the different options and clicking OK.  Alternatively, simply press Ctrl+M (Cmd+M on Mac) to open that display.

There are many useful display options on the Settings menu, so do make use of them to help you get started with these games.

“How can I change the AI settings?”

On the AI menu, you can choose whether to play an AI vs AI game, human vs human, or human vs AI.  You can also use the buttons on the bottom left of the screen to select these options.  Click on ‘Set thinking time (s)…’ on the AI menu to determine how long the AI may think about each move.

“How can I see all the piece types present in each game?”

On the Reports menu, click the ‘List Pieces (Chess family only) option.  After a few seconds, Ai Ai will generate an HTML table showing all pieces present in the current game you have loaded, including their names, piece graphics, abbreviations in the notation, and Ai Ai’s estimate of their material value.

“Why are the piece abbreviations in the move notation different from the previous convention?”

In Ai Ai we need to define promoted and unpromoted forms of pieces separately.  A Lion that appears in the starting position is defined as a separate entity from a Lion that appears when another piece promotes.  In most previous implementations, promoted pieces appear in notation as ‘+[piece promoted from]’, so when a Kirin promotes in Chu Shogi, for example, the resulting Lion is notated as ‘+Kr’.  However, piece promotions often vary across this set of games, so if we wanted to maintain that we’d need to make lots of duplicate pieces to account for these various promotions.

So instead, we opted to abbreviate a piece that appears after promotion as ‘[promoted piece abbreviation]+’, since this allows for consistency across all the games, and no additional duplication of pieces in the code.  So our friend the Lion appears as ‘Ln’ when he starts on the board, and as ‘Ln+’ when he appears by promotion, regardless of what piece he promotes from.  In these historical variants this works fine, because promoted pieces never unpromote, so we don’t particularly have to care what piece they promoted from anyway.

This also means that if new large Shogi variants arise in the future, we can easily add in games with new promotions without needing to add duplicate pieces.  That in turn makes it possible for enthusiasts to make new variants with different promotions without asking Stephen or I for help writing additional code.

However, the situation changes in games with drops, like Tori Shogi, modern Shogi, or Wa Shogi.  In these games, pieces in hand will demote to their previous form, so we *do* need to know what pieces the promoted pieces used to be.  So, in these games pieces maintain the standard notation.

“How do I make those cool animated GIFs of my games?”

At the end of your game, click the Game menu and choose the ‘Review…’ option.  Once the game review screen opens, click the icon that looks like a strip of film to create an animated GIF.

“How can I tinker with the AI and try to improve it?”

On the Settings menu, choose ‘Select Role…’ and give yourself the ‘Superuser’ role.  When you next start Ai Ai, you will have a greatly expanded array of menus and options, many of which will allow you to perform various analyses on games, generate heuristics, test different AI methods and settings, etc.  There’s a lot to play with, Ai Ai has many powerful features for game analysis 🙂

“I have a great idea for a modern variant of these games!  Can you make it for me?”

If you take a look at the .mgl files that define each game, you can see that creating a new variant is pretty straightforward, so long as it can be constructed out of components (pieces and rules) that Stephen has already implemented.  Give that a try first, and if you struggle to get it working, then I can help you to fix it.

“I don’t like the default options you chose for some of these games, and I’m tired of changing them every time.  Can I change them permanently?”

Absolutely.  Just open up the appropriate .mgl file for that game in a text editor, and find the section at the end called “parameters” — this section defines the options that appear when you load the game.  Each option as a default setting, and if you change that to one of the other options listed in the “optionNames” line of that parameter, you will change that default setting permanently.

Just make sure that you save the changed .mgl file with a different name, and keep a backup copy somewhere; otherwise if you copy a new Ai Ai update into the same folder that file will be overwritten by the Ai Ai update.

“Why does the AI struggle with these large Shogi games?”

Ai Ai is a general game-playing framework, and excels at using variants of Monte Carlo Tree Search.  Chess-like games don’t suit these kinds of algorithms very well, so Stephen has added a general Chess-playing engine to make them playable.  However, because of his engine’s amazing flexibility and generality, each specific Chess or Shogi variant has to be optimised separately to get these best out of the engine, and this takes a lot of time and effort.  At this stage we are mainly concerned with getting the games functional, so we haven’t yet engaged in any game-specific optimisation (that will be my job in the months to come).

The main issue though is simply that these games are huge!  Every position has a large number of possible moves to search, and the AI is simply not able to search as deeply as it can in smaller games.  Extending thinking times does help, but even getting 4-5 moves deep requires far, far longer than in smaller games.  Eventually I hope to experiment with using other AI methods for these games, but this will take a lot of time.

So, for now at least, please be patient and give the AI as much time to think as you can stand 🙂

“Hey Eric, why didn’t you include [my preferred rule]?  It’s clearly superior because….”

I completely understand that some modern players would prefer I chose one set of definitive rules, but the problem here is there’s no consensus on what those definitive rules should actually be, and some of these arguments have been going on far longer than I’ve been involved in the Shogi variant world.  That being the case, I’ve decided to opt for a preservation approach, where any rules proposals that are plausible given the historical information we have on these games are kept alive in these implementations and given as an option.

My hope is that over time, the Shogi community will try these various options and decide on a ruleset for each game that we can consider the modern standard.  At that point, I would be happy to revise these implementations to have one ‘standard’ version for each game, and preserve old options in a secondary, customisable implementation, for posterity.

“Hey Eric, why did you include stuff nobody plays anymore, like Hodges’ moves for the Lion Hawk and Free Eagle?”

If a move or rule has been played extensively and is plausible in some way, then I’ve tried to include it, regardless of its popularity.  I initially wasn’t going to include Hodges’ moves, given the modern Tenjiku community seems to have rejected them, but then I read this old correspondence of his on that very issue:

“I well remember my and John Fairbairn’s discussions with our good friend Maruo all those years ago when we were discussing the more exotic variants in his house.  He was absolutely adamant that [the Lion Hawk] does NOT have Lion Power.  There are several points to make.  Firstly, his interpretation is in our mind in no doubt whatsoever.  Secondly, translated text … says words to the effect “…moves like a Lion…”, now this is simply a short way of describing a two-step mover in all directions.  Lion power is something quite different.”

He went on to explain why appeals to logic (“why would the Lion promote to a weaker piece?”) and symmetry don’t work, because plenty of ancient Shogi games include demotion and substantial amounts of asymmetry.

I found this argument reasonably compelling, and given that George was a scholar with connections to Shogi history researchers in Japan and had direct access to the historical sources, we can reasonably assume his opinions on these matters were well informed.  Therefore, I had to consider those moves plausible, and decided to include them as an option.

“Hey Eric, why didn’t you include my Shogi variant?”

We might do that later, but for now the focus is on the historical variants.  Modern variants, particularly modern variants that are already playable elsewhere, are of much lower priority because they don’t need our help to be preserved and made playable.  Also, speaking for myself I prefer to work on variants I have personal experience with, and I am deeply obsessed with large Shogi and much less so with smaller modern variants 🙂

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Powerful pieces in Chess games

In preparation for writing up some detailed articles about my favourite Shogi variants in the future, I spent a bunch of my insomniac hours making Shogi diagrams in Illustrator recently.  I thought I might give these a trial run before the main event, so here’s a more off-the-cuff opinion piece of sorts, about the dominant ‘power pieces’ in Chess and Chess-like games.

UPDATE:  I hadn’t realised my sources on the Tai Shogi pieces didn’t indicate that the power-pieces in fact have slightly different moves!  This then led to the same error popping up in the Long-Nosed Goblin diagram for Dai Dai Shogi.  I’ve now updated the diagrams and text to fix the error.


The Queen as a Power Piece

Abstract game designer Christian Freeling, whom I’ve praised extensively in this blog for his invention of Havannah and Starweb, two world-class strategic games, also invented numerous Chess variants over the years.  Of particular interest is Grand Chess, an enlarged game on a 10×10 board which includes two additional pieces: the Marshall, which has the combined movement powers of a Rook and a Knight; and the Cardinal, which moves as a Bishop or a Knight.  The larger board and larger armies make for a fine game full of strategic and tactical complexity, even more so than standard Chess.

Part of Christian Freeling’s motivation for Grand Chess was his desire to logically ‘complete’ the Chess lineup.  He has spoken in the past about the Queen in Chess, the presence of which he calls ‘defendable but arbitrary’, and the lack of other powerful combination pieces:

There are two more combinations, the ‘marshall’ and the ‘cardinal’. They combine the powers of rook & knight and bishop & knight respectively.  They should not have been excluded because of an arbitrary boardsize, but they were. Chess became a great game where it should have become an even greater game.

My new pet theory is that the exclusion of these other hybrid pieces has actually been a good thing for Chess — not in terms of rule elegance or logic, but in terms of the play experience, and the subsequent success of Chess games with communities of players.  This is not to say that Grand Chess is bad by comparison — far from it, you should definitely give it a try.  Though I do think there’s a reason Mad Queen Chess eventually just became standard Chess — the enormous power gap between the Queen and the other major and minor pieces gives the game additional tension, pace and urgency.   The Queen is a power piece — a singular, dominant force that gives direction and narrative emphasis to Chess play.

Let’s look at an example of the impact of the Queen in high-level Chess — the famous ‘Gold Coin Game’ between Stefan Levitsky and Frank James Marshall in 1912.  Marshall, playing Black, finds himself in this position, with his Queen threatened by capture via Levitsky’s Rook:

marshall-1

23. Rc5 — Black to play.

The next move allegedly ignited so much excitement from the spectators that they tossed gold coins all over the board.  Marshall threw his Queen directly into danger with a surprising and deadly manoeuvre:

marshall-2

23… Qg3!!

White resigned immediately.  White can’t take the Queen — there’s no variation that works for Levitsky.  To give some examples — if White takes with the pawn on h2:

marshall-v1

24. hxg3 Ne2#

Immediate checkmate!  White is trapped by the Knight and the Rook.  If White takes with the Queen:

marshall-v2

24. Qxg3 Ne2+ 25. Kh1 Nxg3+

Black immediately gives the same check with the Knight on e2, takes White’s Queen with check, and will take the Rook on the next move.  White is down a full Rook and completely doomed.  Finally, if White takes with the pawn on f2:

marshall-v3

24. fxg3 Ne2+ 25. Kh1 Rxf1#

Forced mate.  Black gives check with the Knight again, the King must go to h1 due to Black’s Rook, then that same Rook gives mate on f1.  Any other try by White is equally hopeless.

So why is this move so famous?  Of course it’s effective, dispatching White in one fell swoop and eliminating any attempts at a defence.  The move is certainly hard to find, because long lateral moves are notoriously difficult for even strong players to spot.  But we must admit that White was already in trouble here, and it’s not hard to find other, simpler moves that lead to a win as well.

I’d suggest that this move is famous, and by extension all the other notorious Queen sacrifices throughout Chess history, because the Queen is so much more powerful than any other piece that our innate desire is to protect it — the Queen can be a threat from almost anywhere on the board, so every fibre of our being tells us not to throw it away.  The Queen is so important that incredible numbers of Chess problems, studies, and books focus on using it, capturing it, and protecting it.  The Queen towers over the other pieces, so when someone seemingly goes against all good sense and throws her life away, it’s a thrilling moment.  A great Knight sacrifice can be pretty, too, but it doesn’t have the same oomph of a daring Queen sac.

That oomph comes from the Queen’s status as a power piece — a piece that stands alone in each player’s army, capable of dictating the pace and rhythm of the game.  Entire games, and indeed tournaments, can rest on the fate of the Queen.

At this point you might say “OK sure — the Queen is badass, I get it.  But isn’t that just a quirk of Chess?  Is it actually necessary for a great Chess-like game to have power pieces?”  I’m willing to concede that a great Chess game may not need a power piece as a prerequisite for being great.  But the more I thought about this, the more I noticed that every Chess-like game I play has a piece (sometimes two) vastly more powerful and influential than the others on the board.

Since I know the Shogi family very well, let’s take a look at some of Shogi’s power pieces (note that I won’t be looking at promoted pieces generally, since it would just take more time while making no real difference to the overall pattern).  I’m not going to cover every major variant, but a representative slice of six of them — enough to demonstrate that the power piece is not just a fluke of Chess, but a feature common to many games in the King-capture family.

Power Pieces in Shogi

Modern Shogi is well-known for consisting mostly of short-range pieces.  Since captured pieces come back to life all the time in Shogi, the game is less chaotic and more balanced thanks to having predominantly short-range pieces.  However, Shogi still has the Rook and Bishop — two pieces vastly more powerful than everything else, pieces that can devastate your opponent on their own, or devastate you if you lose one or both of them.

In Chess-like games one way of quantifying piece strength is via exchange values.  If we consider the value of a pawn to be 1 point, then we can calculate over many many games the approximate worth of other pieces in terms of pawns.  In Chess, for example, Knights and Bishops are worth about 3 pawns, Rooks 5 pawns, and Queens 10 pawns.  In modern Shogi we see a similar gap between the power pieces and the rest:

shogi-power-pieces-modern-01

The next-strongest pieces behind the Rook and the Bishop are the Gold and Silver Generals, both worth vastly less.  The difference in the mobility of the Rook and Bishop compared to the Generals is particularly striking — on a 9×9 board, with most other pieces being single-step movers or otherwise very constrained, being able to move unlimited distances is seriously powerful.

The Lion in Chu Shogi

Chu Shogi is modern Shogi’s larger ancestor, played on a 12×12 board with 46 pieces per player.  Chu Shogi is an incredibly well-balanced game, and widely regarded by its fans (including me) as possibly the greatest Chess game ever invented.  Chu Shogi is particularly famous for its incredible power piece, the Lion:

shogi-power-pieces-chu-01

Chu Shogi’s Lion is a slice of pure game design genius.  The Lion can move like a King twice in one turn, with all the options that implies — capturing an adjacent piece, then moving back to its starting point (indicated by the ‘!’ in the diagram above); moving any which way in the 5×5 square area around itself, and so on.  The Lion can also jump two squares in any direction (indicated by the stars in the diagram).  It’s agile, powerful, and adaptable beyond any other piece on the board.  The nearest competitor to the Lion is the Queen, which moves exactly like the Queen in Chess (but was invented 300 years earlier); despite the Queen’s massive mobility, it simply can’t compete with the incredible flexibility and brutality of the Lion.

Logically we might think the Lion unbalances the game, but nothing could be further from the truth.  In fact the Lion is so enjoyable and challenging to use that the wise inventors of Chu Shogi included special Lion-trading rules, specifically to ensure that players don’t simply trade Lions on even terms early on to simplify the game.  The Lion in a sense defines the game — Chu Shogi probably would have faded away like so many other Chess variants, were it not for the Lion.

I want to take a moment here to mention Chu Shogi’s big brother, Dai Shogi.  Dai Shogi actually came before Chu Shogi, and includes all the same pieces plus eight more single-step-movers on a 15×15 board (65 pieces per player).  Dai Shogi is often cited as Chu’s slower, less exciting predecessor — I personally disagree with this characterisation, for reasons I’ll get into in a future post, but I believe part of the reason for this is the significantly decreased influence of the Lion on the larger board.  The Lion is still powerful in Dai, but it no longer drives the game — in fact Dai Shogi does not use any special rules to protect the Lion from exchanges, because of its less central role.  This fits as well with my power-piece theory; without the pace and energy of the Lion taking centre stage, Dai Shogi can feel slower, more methodical, and less thrilling than its younger sibling.

Tenjiku Shogi’s Explosive Demons

As we step up to even larger Shogi games, we find that Japan’s ancient game designers were never short of ideas for new power pieces.  On larger boards individual pieces have less influence in general, so to construct power pieces on that scale you have to really get crazy with it.  Fortunately they were up to the challenge.  Tenjiku Shogi is a massive game played on a 16×16 board with 78 pieces per player, and yet again we have a clear standout power piece even on this massive field of battle:

shogi-power-pieces-tenjiku-01

Yes, you are reading that correctly — the Fire Demon in Tenjiku Shogi is worth 83 pawns.  The Fire Demon is also one of the most powerful Chess pieces ever invented.  This beast can move as far as it likes in six directions, or step any which way in a 7×7 square around itself — and whichever way it moves, once it stops every enemy piece adjacent to it is removed from the board.  If the opponent moves a piece next to the Fire Demon on their turn, that piece gets burned away too.

So instead of Tenjiku Shogi being a bigger, slower version of Chu, the Fire Demon turns it into a sort of supercharged extended edition.  Pieces die violently and in large numbers, and games can be over in surprisingly short amounts of time.  Note that the next two most powerful pieces in the game, the Great General and Vice General, are also staggeringly strong, able to jump over any number of friendly or opposing pieces in order to perform a capture.  Even with that significant power these pieces still are only half as strong as the mighty Fire Demon.  Like the Lion and the Chess Queen, the Fire Demon is in a class by itself.

Dai Dai Shogi’s Hook Movers

Dai Dai Shogi — literally translated that means ‘Big Big Shogi’ — is an extremely sizeable game, played on a 17×17 board with 96 pieces per player.  Once again the sheer enormity of the board didn’t deter our intrepid designers from producing yet another power piece:

shogi-power-pieces-dai dai-updated-01

Our friend the Lion is back, but this time as only the third-most powerful piece on the board.  Towering above him are the hook-moving pieces; these monsters can move as far as they like in one direction as a Rook or Bishop, then turn 90 degrees and do it again, all in one turn (although they may only capture once).  In the case of the Hook Mover — worth a ridiculous 114 pawns — that means on an empty board it can reach any square in a single move.  That single piece is considered to be worth more than five Lions.

R. Wayne Schmittberger in a 1981 issue of Shogi Magazine had this to say about the power of the Long-Nosed Goblins and Hook Movers in Dai Dai Shogi:

The dominant piece in the middle game is the Long-Nosed Goblin, and in the endgame the supremely powerful Hook Mover, which not only attacks every square on an empty board but gives double-check by itself!!  This makes interposition against it impossible in many cases.  Generally a game will end quickly if a player is able to get the deadly combination of a Hook Mover and a Furious Fiend near the enemy King, where they will simply run amok and eventually combine for an elegant tsume [mate].

This power piece isn’t just a random addition, it’s carefully integrated into the fabric of the game.  Dai Dai Shogi is notable for having a very asymmetric initial position; there are 64 different types of pieces in each player’s 96-piece starting army.  The Hook-Mover and the Long-Nosed Goblin are tucked snugly away in the back ranks, waiting to be unleashed when the board is open and starting to empty of other pieces — precisely when they’re at their deadliest.  As R. Wayne Schmittberger says, the middle- and endgame of Dai Dai Shogi is heavily influenced by these pieces, and the tactical complexities they introduce alongside the huge menagerie of different pieces gives the game a unique flavour.  Thanks to this tactical and strategic richness, Dai Dai Shogi stands out even in the crazy world of Shogi variants.

Hook Movers in Maka Dai Dai Shogi

Next up is Maka Dai Dai Shogi, one of my favourite Shogi variants.  Maka Dai Dai is an immense game, played on a 19×19 board with 96 pieces per player, and is notable for its strange pieces named after mythical spirits, and for the fact that the King promotes into the near-omnipotent Emperor that can jump instantly to anywhere on the board.  Even on this larger board, the Hook Mover still works perfectly as a power piece:

shogi-power-pieces-maka dai dai-01

Once again the Hook Mover towers over the rest, worth more than double its nearest competitor.  The Buddhist Spirit, which moves as both a Lion and a Queen and has special rules that make it essentially immortal, still pales in comparison.  In fairness, one could say  in this case that the ultimate power piece in Maka Dai Dai Shogi is the Emperor, which is so unbelievably strong that the entire game changes completely when a King promotes.  But the Emperor doesn’t always appear, while the Hook Mover is always lurking, ready to cause trouble — so in that sense I consider the Hook Mover the real power piece here, because it always will impact on the game.

Tai Shogi: on the biggest boards, mobility is King

Our last stop on the Large Shogi Express is Tai Shogi, a monstrosity of a game played on a 25×25 board with 177 pieces per player.  Here once again the Hook Movers reign supreme, and in practice are even more powerful with the extra room to manoeuvre on such a gargantuan board:

shogi-power-pieces-tai-updated-01

In Tai Shogi all the strongest pieces are hook-movers of some description, but the double-Rook Hook Mover still rules the roost, and it’s not a close competition.  On this massive board rich with weak targets, the Hook Mover’s value jumps up to a preposterous 232 pawns, well over twice the value of its double-Bishop brethren.

Note that the Capricorn and Long-Nosed Goblin have slightly different piece values; the Long-Nosed Goblin is able to move one square orthogonally, as well as having the double-Bishop move, so it is slightly more powerful.  This option to spend a turn to switch diagonals means the Goblin can actually reach every square on the board, instead of half the squares.  However, spending a whole turn on this when you have 177 pieces to move is rather costly, so this does not create a huge difference in piece value.  Also, the Capricorn promotes to Gold General, whereas the Long-Nosed Goblin does not promote; since the Capricorn’s promotion is actually a demotion, this means it has to be used more cautiously.  That being said, before demotion the Capricorn remains a deadly threat and incredibly mobile.

R. Wayne Schmittberger, noted Shogi variant expert, underlines the importance of the hook-moving pieces in all these titanically large games:

Tai Shogi is the ultimate marathon game in the Chess family.  In terms of the number of pieces and playing time, Tai Shogi is to Dai Dai Shogi what Dai Dai Shogi is to Chu Shogi.  A serious game will require several long playing sessions to complete and will usually require more than 1,000 moves per player.   Like Dai Dai and Maka Dai Dai, Tai has hook-moving pieces that dominate the board in much the same way that a Lion does in Chu Shogi.

Tori Shogi’s Menagerie

Now to allay any fears that only huge and ridiculous Chess-type games fit my theory, let’s take a moment to look at Shogi’s elegant little sibling, Tori Shogi:

shogi-power-pieces-tori-01

Tori Shogi is a diminutive game, particularly in comparison to the others we just looked at — the board is only 7×7, and each player starts with a mere 16 pieces.  Yet even here we see a similar dynamic — only one piece, the Eagle (a promoted Falcon), has unlimited movement range of any kind.  As a result, the Falcon’s value is nearly double that of its ancestor.  Granted, in this case the Eagle isn’t present from the start, but the action in Tori Shogi is frenetic enough and the Eagle powerful enough that it often has a strong influence on the game.

Stepping away from Shogi for a moment, we can see that the same properties appear in other popular Chess games too — like Xiangqi and Janggi (Chinese and Korean Chess, respectively), where the Chariot is about twice as strong as its nearest competitor (the Cannon):

Janggi-Xiangqi-power-pieces-01

Xiangqi is frequently cited as the most popular traditional board game in the world, and Janggi has a robust professional scene in Korea and a growing international player base, so once again we see that power-piece Chess games tend to attract a robust following.  Incidentally, both these games are very different from Chess and Shogi, and well worth your time — I’ll be discussing them in detail in future posts.

I admit that my knowledge of Chess variants is by no means encyclopaedic, but I argue that the prevalence of power pieces in notable Chess variants suggests that the seemingly unbalanced starting setup of many games in this family is actually an asset, not a weakness.  The Chess variants that have survived the centuries and retain a following today seem to share a predilection for the power piece.

I can certainly understand that having a single dominant piece type might strike a game designer’s mind as distasteful, but from the perspective of the player, power pieces give these games an exciting dynamic.  In the case of the large Shogi games,  they stay playable and interesting largely because of these power pieces — without them, these games would drag on forever, and with so many slow-moving targets plodding around there’d be far fewer thrills in any particular capture or sneaky tactical sequence.  But a nuclear Fire Demon sacrifice destroying eight pieces in one go?  Yes, please!

So, in contrast to Christian’s view, I’d say that Chess and its many cousins has achieved cultural-icon status partially because the starting position is illogical and lopsided in its distribution of power amongst the pieces.  The ubiquity and popularity of the power piece across the games profiled here suggests that this dynamic appeals to players across the centuries and across cultures, and that it translates equally well to large and small boards and starting arrays.

Mitrofanov’s Deflection

Before I leave you, I want to showcase another famous Queen sacrifice in Chess.  This example comes from an endgame study.  Chess endgame studies are carefully composed endgame problems where one side must win or draw, and a properly-composed study must have one, and only one, correct solution.

This particular problem was composed by Leopold Mitrofanov at an endgame study competition in 1967.  The problem opens with Black pushed into a corner, but armed with two Knights and a Bishop, and threatening to promote a pawn any second:

mitrofanov-1

White to play and win.

White can win here, presumably via one of those pawns on the right side of the board.  However, those pawns are less advanced than Black’s, so the first question for White is: how to delay that dangerous pawn?  First, White can push back the opposing King by pushing the b-pawn, then offer a Rook sacrifice:

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1. b7+ Ka8 2. Re1!

Black must take the Rook to get his pawn through, which gives White a chance to sneak in an advance of the g-pawn.  Both sides end up promoting their pawns to Queen shortly thereafter, and Black retreats the Bishop to protect the King:

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2… Nxe1 3. g7 h1=Q 4. g8=Q+ Bb8

Now things get a bit heated.  First, White pushes the a-pawn, cramping Black’s King, and Black retaliates with a Knight check.  White takes the Knight, but then Black’s Queen jumps into the action and takes White’s h-pawn:

mitrofanov-4

5. a7 Nc6+ 6. dxc6 Qxh5+

This looks really bad for White!  Black’s King is protected in the corner, the White Queen is off in the other corner, and Black’s Queen now has free reign to chase down White’s King.  There’s nowhere for the King to go.

Luckily there’s another option other than a King move:

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7. Qg5!!

Outrageous.  White plants the Queen directly in front of Black’s Queen, blocking the check — but then Black can take it for free, and White’s in check again!  What’s the point?

The point is to deflect the Black Queen.  Black must take the Queen, and in so doing takes his own Queen off a key diagonal.  Now when White retreats his King to a6, Black can’t immediately give check:

mitrofanov-10

7… Qxg5+ 8. Ka6

Suddenly, Black is in terrible trouble!  His Knight is out of play on the bottom of the board, and the Queen has the White King trapped but can’t do anything with it.  White, despite having only a few pawns left, has the upper hand.  Black captures the a-pawn with his Bishop, hoping to whittle down the advancing horde, then sacrifices his own Queen to draw the King away from the defence of the pawns:

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8… Bxa7 9. c7 Qa5+

Unfortunately these desperate tactics lead nowhere.  Black’s Knight is useless, and his King can’t capture both pawns at once, so one promotes to Queen:

mitrofanov-9

10. Kxa5 Kb7 11. bxa7 Kxa7 12. c8=Q (1-0)

It’s over!  White has a Queen and Black is completely out of options.  White can easily drive Black’s King into the corner and force mate in a couple of moves.

Mitrofanov’s ingenious study has all the hallmarks of a classic — a clever solution, a glorious and counterintuitive Queen sacrifice, and a Rook sacrifice too.  No wonder it’s been called ‘the study of the millenium’.  For me, it’s another example of the powerful psychological impact of the Queen sacrifice; the winning move 7. Qg5!! strikes us as so absurd that the solution seems even more creative and beautiful.

 

 

 

 

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An Introduction to Shogi

ANNOUNCEMENT:  There will be a special event at my workplace, the MRC/CSO Social and Public Health Sciences Unit, running at 5PM on 7 February 2020.  Dr Shuzo Sakata of the University of Strathclyde, Shogi player and teacher, will be showing us all how to play Shogi!  Sets will be provided — please RSVP to me directly if you plan to come, to ensure we have enough sets.  

What is Shogi?

Shogi is the Japanese form of Chess, the ‘royal game’, in which two players vie to be the first to checkmate their opponent’s King — meaning their King is unable to escape capture on the next move.  Many centuries ago, when the ancient ancestor of Chess called Chaturanga was developed in India, the game spread across Asia and Europe, spawning new variations in every region that embraced the game.  Shogi is first recorded in the Heisei Era in ancient Japan — around the 11th century — where it rapidly developed into its own, unique take on the royal game.

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My traditional Shogi set — a Shin-Kaya board, with hand-carved pieces made from Japanese maple, with the kanji (Japanese characters) carved in the Minase calligraphy style in lacquer

How is Shogi different from Chess?

Shogi does share the same goals as Chess — checkmating the enemy King — and shares some of the same pieces.  However, many of the fundamentals are quite different:

  • The Board: a Shogi board is a 9×9 playing area of 81 squares, compared to the 64 squares of the chessboard.  The board is not chequered either.
  • The Pieces: Chess has six types of pieces: Pawns, Knights, Bishops, Rooks, Queens, and Kings.  Shogi has ten: Pawns, Knights, Silver Generals, Gold Generals, Lances, Rooks, Bishops, Dragons (Promoted Rooks), Horses (Promoted Bishops), and Kings.  Some of the shared pieces move differently, too: Knights make the same L-shaped jump but only forward; and Pawns move and capture only directly forward.
  • Promoting Pieces: In Chess, pawns that reach the enemy’s back rank can promote to become a Knight, Bishop, Rook, or Queen.  In Shogi, any piece that reaches the enemy camp (the three rows where their pieces begin the game) can promote.  A promoted piece flips over, and the other side of the piece indicates their promoted form.  Promoted Bishops (Horses) and promoted Rooks (Dragons) are the most powerful pieces in the game.

Shogi’s Ingenious Addition: Drops

There’s one major rule change that was added to Shogi in the 16th century and has come to define the game ever since: drops.

In Shogi, when a piece is captured, it is truly captured — it becomes the property of the capturing player.  The capturer places the piece on a small side-board called a komadai (piece stand) and holds it in reserve.  At any point from then on, they may forgo a normal move and instead drop a captured piece to any empty square on the board!  

However, an important point to remember: promoted pieces, when captured, are demoted.  Any dropped piece must be moved into the promotion zone again to be promoted.  Two other key exceptions: Pawns cannot be dropped so that you have more than one of your pawns on a single vertical line; and pieces cannot be dropped in a space where they have no legal moves.

Drops make Shogi play and feel very different from Western Chess.  Since captured pieces come back to life throughout the game, the number of pieces on the board stays roughly the same throughout — there are no endgame situations with near-empty boards, as in Chess.  The constant back-and-forth of captures and drops makes a Shogi game dynamic, aggressive and fierce — attacks are frequent, and giving up the initiative to play defensively is risky.

Thanks to drops, Shogi is also much more decisive than Chess — less than 2% of professional Shogi games end in a draw, a staggering difference from the ~60% draw rate of professional chess!

Is Shogi hard to learn?

Not really!  The biggest obstacle for most new players is learning the pieces — as you can see in the photo of my Shogi set above, all Shogi pieces are the same shape and colour, and the two players’ armies are distinguished by the pieces’ orientation (aim pointy bits at the enemy!).  The different pieces have their names written on them in Japanese kanji characters, which are not so easy to learn for people who don’t speak Japanese.

However, the best way to learn is to simply dive in — after a game or two, the kanji fade away and are easy enough to recognise.  I find it helps beginners to forget they are letters — this tends to prime us to try to divine their meaning, which makes them more intimidating.

Instead, just think of them the same way as you think of the shapes of Western Chess pieces — both are abstract shapes, and neither really relates to what the piece does or how it moves.  The kanji are effectively just symbols, just like the odd shapes of Chess pieces.  Also, you only really need to recognise the top characters on each piece — that’s enough to distinguish all the pieces from each other.

Other than that, it’s just a bigger version of Chess!  The steepest part of the learning curve after that is getting comfortable with the powerful impact of drops — this is especially strange for seasoned Chess players, who will be accustomed to captured pieces playing no further role in the game.  But again, given a few games, you’ll soon start to see the exciting, combative play allowed by the drop rule, and you’ll be chucking Gold Generals at your opponent like a pro.

How the Shogi Pieces Move:

Here’s a quick reference to the moves of the Shogi pieces:

evans-shogi-move

As you can see, the King, Rook and Bishop move the same as in Chess.  The Knight moves the same as in Chess too, but can only jump forward.  The Pawn moves forward and captures forward — no diagonal capturing like in Chess.  The Gold General moves one space in any direction except diagonally backward, while the Silver General can move one space diagonally in any direction or one space directly forward.

The promoted pieces are easy to remember — all promoted pieces move the same as the Gold General, with the exception of the Horse and Dragon.  The Horse moves like a Bishop, but can also choose to move one square orthogonally; the Dragon moves like a Rook but can also move one square diagonally in any direction.

You might notice that the Shogi pieces have a general forward bias in their movement patterns, and most are short-range movers.  This works very well with the drop rule — the combination of forward movement and drops favours attacking play, and the short-range movements prevent the game from becoming too chaotic, as it might be with powerful pieces appearing wherever they like on the board.

The flip side to this is that you can very occasionally have a condition called entering Kings, where both players’ Kings have moved into each others’ promotion zones.  This makes it very difficult for anyone to win, as most of the pieces attack forward rather than backward.  This is one of the few ways you can have a draw in Shogi.  In practice this rarely happens, especially between beginners, who normally dive heedlessly into battle and neglect King safety entirely!

Note that the Horse provides a good reason for the Shogi board to not be chequered.  In Chess your Bishops are confined forever to half of the board — either the black diagonals or the white ones.  The Horse however can spend a move to shift from one set of diagonals to the other, so it’s less useful to have the chequers to indicate where the Bishops go — once promoted they can go anywhere.

Shogi: A whole family of amazing games

One of the things I love about Shogi is that, in a sense, it’s part of a whole game system rather than a single game.

To unpack that a little bit — you may be aware that there are many hundreds of Chess variants out there, variations on the game with different boards, pieces and rules.  Shogi has these too, but unlike in Chess, many of the Shogi variants are hundreds of years old, and were refined over the centuries into fantastic games in their own right!  Shogi variants are well-designed, well-balanced, and offer just as much intrigue and fascination as the traditional form of the game.

In fact, before the introduction of the drop rule made the modern game dominant, there used to be three variants of Shogi that were commonly played: Sho Shogi, or ‘Small Shogi’, which added drops later and become modern Shogi; Chu Shogi, or ‘Middle Shogi’, a much bigger game played on a 12×12 board of 144 squares; and Dai Shogi, or ‘Large Shogi’, played on an even bigger 15×15 board of 225 squares.  Shogi used to come in Small/Medium/Large sizes!  Alongside these main variations, there were numerous other variants of Shogi developed over the centuries, some of which I’ll describe below.

Today, besides Sho Shogi only Chu Shogi maintains a small presence — the Chu Shogi Renmei in Japan is the official governing body, and holds regular tournaments.  This is unfortunate, really, as the Shogi variants are quite unique — particularly the larger variants, which are far larger than any commonly-played Chess variants, and offer hugely creative pieces and styles of play.

Thankfully, the efforts of one George Hodges in the late 20th century led to the revival of these ancient forms of Chess, and remarkably he even manufactured affordable sets for most of the large variants.  Sadly George left us a few years ago, but his wife carries on that business, and she remains the only source on the planet for physical sets of most of the Shogi variants.  I of course have bought several of them myself 🙂

Without further ado, here’s a brief intro to a few of the more spectacular Shogi variants — several of which I will bring with me to the Shogi event in a few weeks time!

Tori Shogi

Tori Shogi, or ‘Bird Shogi’, is an action-packed small variant of Shogi that packs a lot of action into its 7×7 board of 49 squares.  At the start of the game, each player has 16 pieces in their camp — the board is more dense with pieces than in any other Shogi variant.  To play you need to remember nine distinct piece movements, one less than normal Shogi.

Unlike most Shogi variants, which build on a common foundation of pieces that generally behave the same across many games, Tori Shogi uses an entirely new set of pieces named after birds (hence ‘Bird Shogi’).  Instead of Pawns we have Swallows, we have Quails that move differently depending on which side of the board they start on, the King is now a Phoenix, and so on.

Like modern Shogi the game uses the drop rule, but with one major modification — in Tori Shogi you can drop a second pawn (Swallow) on a file where you already have one.  In fact this is already happening in the start position, as you can see below!  This rule heavily impacts Tori tactics, and also helps the board to not feel too constrained despite having so many pieces everywhere.

Tori-shogi-board1

A Tori Shogi set from Angela/George Hodges — the top pieces have been flipped to show off their promoted forms.  In this game only Swallows and Falcons promote.  Note that the Swallows are in conflict right from the start of the game!

Tori Shogi is somewhat unusual among Shogi variants in that it was invented more recently — in 1799 to be precise.  This means we have a fair bit more information on high-level play in this game than some of the others, where unfortunately top players’ games are lost in the mists of time.  For Tori Shogi we have a few games from a tournament played between top-level Shogi professionals, some clever tsumeshogi (checkmate puzzles), and even a recently-updated English book on the game, The Way of Tori Shogi!

Tori plays in a very unique way, not just because of the small board and two-pawn drop rule, but also because the pieces are somewhat strange.  The movements themselves are odd, but also the promoted Swallow turns into a Goose that moves in a bizarrely useless way (jumping one square diagonally forward left or right, or one square backward).  Promotion is manda-Tori (sorry) in this game, so you have to have some clever plans afoot to use these weird pieces to achieve checkmate.

In any case, Tori Shogi is an exciting and unique game, and unlike some of the other variants there’s some good information out there on how to play well.  I recommend picking up a set and a copy of The Way of Tori Shogi and giving it a go!  Or just play with me, I already have a set 🙂

Tori-shogi-moves

The moves of the Tori Shogi pieces.  Clockwise from top left: Swallow, Falcon, Left Quail, Right Quail, Crane, Goose, Eagle, Pheasant, Phoenix.

Wa Shogi

Wa Shogi, or ‘Harmony Shogi’, marks our first step into the world of the larger Shogi variants played on boards bigger than the standard 9×9 grid.  This game is played on an 11×11 grid of 121 squares, with each player having 27 pieces at the start of the game (compared to 20 in Shogi).  To play, you have to remember 20 distinct movement patterns for your pieces (compared to 10 in Shogi).

Wa Shogi is an interesting beast — similar to Tori Shogi, Wa Shogi uses all non-standard pieces, and none of the pieces share their names with the standard Shogi pieces.  Some do have equivalent moves to the standard pieces, but most are different.  The pieces in Wa Shogi are named after animals — moving beyond just birds, as in Tori Shogi, we have fun stuff here like the Violent Wolf and the Climbing Monkey.

Not only that, but out of the initial starting setup for each player, there are only multiples of the Sparrows (pawns) — all the other pieces are different.  That means there’s quite a few interesting tactical options in this game.

Wa Shogi is also unusual in that, unlike the other large Shogi variants, Wa Shogi was quite possibly played with drops.  The game was invented after the drop rule became popular in 9×9 Shogi, and the Edo Era sources we have on Wa Shogi mention additional tactical options over the other variants, without specifying precisely what they mean; this could indicate the use of the drop rule.  Additionally, some promoted pieces have identical moves, but are named differently and come from different unpromoted pieces; some suggest this indicates the use of drops, as dropped pieces are unpromoted so these cases would benefit from differentiating the promoted forms for ease of play.

Most modern players play Wa with drops, and the general consensus is that the game plays very well this way, so I definitely recommend using them.  Wa Shogi is a fun change of pace from the traditional game, with the odd new pieces with weird moves and cool names, and the increased freedom of the larger board with drops adds a fun dynamic.

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The starting setup for Wa Shogi, with the second player’s pieces flipped to show their promoted sides.  Only three pieces don’t promote in Wa.

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A closeup of the Crane King — in the centre of the bottom row — protected on either side by a Violent Stag (left) and Violent Wolf (right).  Lot of violence going down in this game.

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A move reference for Wa Shogi, included here mainly to show off the cool names for the pieces!

Chu Shogi

Chu Shogi is a spectacular game.   Those lucky few who have played it frequently class it as one of the finest Chess games ever invented — and I thoroughly agree.  The game is thought to have been invented in the 13th century and is one of the oldest forms of Shogi.

The game is not super accessible at first — the board is much larger than in Shogi (144 squares vs 81), and there are far more pieces on the board (46 pieces per player, compared to 20 each in Shogi).  All told, you’ll have to remember 28 different piece movements instead of 10 like in Shogi!  But the rewards are very much worth it.

Chu Shogi, like the other larger Shogi variants, does not use the drop rule — otherwise the games would go on far too long!  Instead captured pieces are lost permanently, as in Chess.

Despite the large board and huge armies, Chu Shogi maintains a pretty swift pace.  Each player starts with powerful pieces on the board from the beginning — including multiple Dragons and Horses, and the Free King which moves as a Queen in Chess.  Interesting to note here that the Queen in Chess was invented three centuries later — Chu was an extremely innovative game for the time.

The most powerful piece, and the piece that defines Chu Shogi, is the Lion.  The Lion effectively moves twice in one turn — it can make two consecutive King moves in any direction, with all that implies: it can capture twice; capture once and return to its starting square, appearing to capture without moving; or it can move once then return to its starting point, effectively passing its turn.  All of these abilities are staggeringly powerful for different reasons.  The Lion is so important and so engaging that the Chu community wisely added some rules to prevent players trading them off early in the game — it’s a bit complicated, but essentially you can’t sacrifice your Lion for your opponent to recapture unless you captured a sufficiently powerful enemy piece in the process.

Notably, Chu Shogi includes a piece called a Drunk Elephant, which moves like a King except it can’t move directly backward.  This piece promotes to Crown Prince, which is a second King — and both Kings and Princes must be captured to win the game!  Because of this, Chu and the other large variants with Drunk Elephants (most of them) don’t actually have a checkmate rule — any royal pieces must be actually captured to win the game.  This allows you to sacrifice a Prince or King for tactical reasons — although honestly that’s rarely advisable!

At any rate, it’s a fabulous game, definitely worth your time if you’ve ever enjoyed a game of Shogi or Chess.  It’s also the root of many of the larger Shogi games, meaning if you can play Chu it’s easier to jump up to the larger games afterward.

chu-shogi-set

My Chu Shogi set, in the initial position.  Board purchased from Aoyama Gobanten in Tokyo, pieces from Angela/George Hodges in the UK.  The powerhouse Lion is two squares above the King, if you’re wondering.

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The end of a Chu Shogi game — White wins after 288 moves (!), fittingly enough with a Lion checkmate.  Check out the huge piles of dead pieces on the side of the board!

chu-shogi-mega-tsume1

A rather spectacular Chu Shogi checkmate puzzle I found online — Black (bottom) to win in 3,257 moves!  The puzzle is well-formed, meaning there’s only one possible solution.  Good luck finding that one!

Dai Shogi

Dai Shogi, big brother to Chu, is much bigger than its sibling but not that much more complicated to learn.  Essentially, take Chu, add eight more piece types with fairly easy-to-remember short-range moves, all of which promote to Gold General, and you have Dai!

Some criticise Dai as being too slow or not exciting enough, given that it’s essentially a scaled-up version of Chu with more pieces and a bigger board.  But I strongly disagree — the larger board significantly expands the options available to players, the larger armies make the game more forgiving given the lower importance of material losses, and the powerhouse Lion is less dominating on the larger playing area.  The game is indeed slower, but it’s also strategic, intriguing, and a great introduction to the larger Shogi variants given it’s easy to pick up once you know Chu.

dai dai vs shogi comparison

A comparison of Dai Shogi (left) vs modern Shogi (right) — turns out that Large Shogi is, in fact, large

dai shogi closeup

A close-up view of the King’s vast entourage in Dai Shogi.  To either side he’s flanked by his faithful Gold  and Silver Generals; to the front a Drunk Elephant and two Blind Tigers; then in front of those, dangerous beasts like the Lion, Kirin, Phoenix, Evil Wolves, Dragon Kings and more.

dai-shogi-aftermath-568moves copy

A Dai Shogi game I won online — after a mere 568 moves.  Note my opponent threw a ‘spite check’ at me when he knew he was done for — even if I didn’t have checkmate on my next move, my Cat Sword (cool piece name) would’ve instantly recaptured his attacker anyway.

Tenjiku Shogi

Tenjiku Shogi — sometimes translated as ‘Exotic Shogi’ — is one of the most unique and dynamic games of Chess ever devised.  The game is played on a massive 16×16 board (256 squares), and each player starts with 78 pieces in their army — and yet, the pieces are so powerful that the game can be over in less moves than a game of regular Shogi!

Like Chu Shogi is defined by the Lion, Tenjiku is defined by the Fire Demon.  Each player starts with two of these.  The Fire Demon can move as far as it wants in six directions — already extremely powerful by Shogi standards.  Not only that, it can make a three-step area move — three consecutive King moves in any directions (but only one capture, for reasons that will soon become obvious).  But on top of that, it burns everything it touches!

In other words, the Fire Demon instantly kills any piece adjacent to it when it finishes moving, meaning it can capture up to eight pieces in one move.  Not only that, but if the opponent isn’t thinking and moves a piece next to it on his turn, that piece is also instantly captured — and that doesn’t count as your turn!

In addition to the two Fire Demons, your army also contains a Lion, five other pieces that can capture multiple times in a turn, two pieces called Water Buffaloes that promote to Fire Demons, and a number of range-capturing Generals — these are pieces that can jump over any number of enemy pieces in order to make a capture (each player has six of these).  The upshot of all this is that, right from the opening, Tenjiku is a dynamic and dangerous game — attacks start immediately, and your huge 78-piece army starts dwindling very quickly.  No other Chess variant plays like this, and it’s an absolute blast.

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A Tenjiku Shogi set from Angela/George Hodges — the top player’s pieces have been flipped to show off their promoted sides.  Of course I also own one of these sets.

tenjiku vs shogi comparison

Traditional Shogi lined up beside Tenjiku — just think how much damage one Fire Demon could do in that Shogi game!

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A closeup of the deadly Fire Demon, ready to wreak havoc

Dai Dai Shogi

Dai Dai Shogi — or, literally translated, ‘Big Big Shogi’ — definitely fits its name.  The game is played on a 17×17 board of 289 squares, with each player leading an army of 96 pieces!  The starting setup, unlike most Shogi variants, is highly asymmetric — amongst the 96 pieces in your army, there are 64 different types of pieces, so many of your army are unique single pieces.  All told, you need to remember 68 different piece moves — again unlike most variants, only 20 pieces promote in this game, and none of those promotions are to Gold General.

Dai Dai is quite a fascinating game, with a style of play all its own.  This is the first large Shogi game to introduce promotion by capture — pieces promote as soon as they capture any enemy piece, and don’t have to wait until they reach the promotion zone.  Promotion is also mandatory, whereas it’s optional in standard Shogi.  This creates some intriguing tactical decisions, as some pieces effectively demote, becoming weaker when they make a capture — so you’d better make that capture count!

Dai Dai also introduces two powerful hook-moving pieces: the Tengu, or long-nosed goblin, that can make two consecutive Bishop moves at right angles to each other; and the aptly-named Hook Mover, which makes two consecutive Rook moves at right angles to each other.  If that doesn’t sound so amazing, consider that a Hook-Mover on an empty board can reach any square in one move — hard to keep your King safe from that!

Dai Dai Shogi is well worth a try if you’re interested in a unique twist on Shogi — the asymmetric setup, huge piece variety and powerful hook-movers make for a surprisingly aggressive game, considering the size of the board.

dai dai vs shogi comparison

Big Big Shogi indeed!  Board and pieces from Angela/George Hodges once again.

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Dai Dai Shogi set with the second players’ pieces flipped to show the promoted sides.  Note how few of the pieces promote — not even the pawns!

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The King’s entourage grows ever larger, and more diverse.  Out of the 64 starting pieces, a full 47 of them are solo pieces, making for a complex and asymmetric starting position.

Maka Dai Dai Shogi

Maka Dai Dai Shogi is yet another step up in size from Tenjiku, played on a 19×19 board of 361 squares, with each player starting with an army of 96 pieces.  The name is a bit interesting — ‘Dai’ means big or large, as we know, and ‘Maka’ is a word derived from Sanskrit that means something like ‘Superior’.  So ‘Maka Dai Dai Shogi’ means basically ‘Superior Large Large Shogi’, or less awkwardly, ‘Superior Ultra-Large Shogi’.  I would argue this is pretty accurate — it’s definitely ultra-large, and has a number of superior qualities.

One of the standout qualities of Shogi as compared to Chess is that most of the pieces can promote, and the large variants for the most part carry on this tradition.  Maka Dai Dai, however, takes it to the next level, and allows the King himself to promote!  A promoted King becomes an Emperor, the most powerful piece to exist in any variant of Chess: the Emperor can instantly teleport to any unprotected square on the board, including squares occupied by enemy pieces.  In other words, the Emperor can instantly go anywhere and capture anything, so long as that square isn’t directly threatened with recapture by an enemy piece.

Alongside this, in Maka Dai Dai promotions occur by capture, as in Dai Dai Shogi — however here the promotion is optional, unless the captured piece is a promoted piece, in which case promotion is mandatory!  This helps to speed up the pace of the game, as on such a large board reaching the promotion zone would take forever.  Hook-moving pieces appear again in this game, but here they demote to Gold General on capture, so they’re effectively one-shot nuclear weapons if used to take out a promoted piece — use them wisely.

Promotion-by-capture also makes attacking the enemy King a risky proposition — if you mess it up, the King might capture an attacking piece, thereby immediately becoming an Emperor, which is both extremely powerful and desperately hard to checkmate!

“If you come at the King, you best not miss.”

–Omar Little

Maka Dai Dai, like most of the large Shogi variants, was invented by Buddhist monks — after all they have lots of time on their hands.  This is more apparent in Maka Dai Dai than the other variants, as it includes pieces drawn from Buddhist mythology that behave in unusual ways.  The Deva and Dark Spirit, for example, promote to Buddhist Spirit and Teaching King respectively — and any piece that captures them becomes a Buddhist Spirit or Teaching King, so these immortal creatures effectively never leave the board.

Substantial research has been done on this game by Professor Tomoyuki Takami, who states that Heian-Era sources suggest that Maka Dai Dai was actually one of the earliest forms of Shogi to exist, dating from as early as the 10th century.  He says that the pieces of the game are inspired by Chinese astrology and traditional masked dances and festivals of the early Heian era, and that in the early days the game was played as a form of ritual rather than entertainment.  Over the centuries, the game was reduced down to smaller forms, like Dai Dai Shogi, Dai Shogi and Chu Shogi, once they discovered that this ritual game was actually quite fun to play, but pretty long….

How long, you ask?  Well, George Hodges once compared the lengths of various versions of Shogi — this is the number of total moves in an average game for each variant:

  • Chess: 80
  • Shogi: 110
  • Dai Shogi: 400
  • Dai Dai Shogi: 800
  • Maka Dai Dai Shogi: 1100
  • Tai Shogi: 2000

Wow, that’s long.  If you start up a game of Maka Dai Dai Shogi, make sure you have the weekend free 🙂  I should say that I, of course, own a physical set for this game and would happily play it with anyone who asks.  The board is too big for my table, however, so we’d have to find a place big enough!

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A Maka Dai Dai set by Angela/George Hodges — promoted pieces on top.

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Maka Dai Dai is such a large game that it can be quite intimidating — staring across the board at your opponent’s massive army lurking across the horizon feels quite different from more normal-sized Chess games.

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The Mighty Emperor

 

Tai Shogi

OK, now this is getting ridiculous — Tai Shogi, or ‘Supreme Shogi’, is a spectacularly huge game played on a 25×25 board of 625 squares, invented in the 15th century by Buddhist monks (of course).  Each player marches into battle with an army of 177 pieces each, and in order to play you need to remember 99 distinct piece movements.

I’ve never personally played this, but remarkably, you can actually buy a set of this from Angela Hodges here in the UK.  The board is more than a metre square!  Even experienced players take upwards of two hours to set up the pieces in their initial position.  As you can see below, each players’ starting ranks are absolutely chock full of pieces — in fact the opening phase is a bit like a sliding-block puzzle as you try to free up lines for your pieces to get into the action.

Notably, there are actually no Kings on the board — each player starts with an Emperor in play (!), and a Crown Prince that moves like a King.  Both must be captured to win the game.  Many of the other pieces have strong promotions, which occur by capture as in Dai Dai and Maka Dai Dai rather than by entering the promotion zone — so carelessly leaving pieces out to be gobbled up can rapidly turn the game against you!

Those who’ve played Tai say it’s an extremely challenging game, because it’s very hard to formulate any kind of sensible whole-board strategy in a game this large.  As a result the game plays more like a wargame, with intensely tactical local skirmishes of great complexity breaking out across the board.  Meanwhile, the everpresent Emperors make each move feel consequential — leave anything hanging and you may give the Emperor a chance to start some carnage.  Given how old this game is, the creativity of all this is astounding — it’s kind of like an ancient version of Warhammer or something.

I don’t yet own this game but certainly plan to at some point — consider this a standing challenge to all!  Once I get a set for this, I’m happy to give it a go with anyone who’s interested.

tai shogi vs shogi comparison

Regular Shogi just looks tiny compared to Tai Shogi!  Without a doubt you could play an entire Shogi tournament in the time it takes to play one game of Tai Shogi.

tai shogi central files

A closeup of the Emperor’s immediate surroundings — quite a dense wall of protectors he has!  The Emperor is at the centre of the bottom row, the Crown Prince (taishi)  is directly above him, and the Drunk Elephant three pieces above the Prince.

Taikyoku Shogi

Unbelievably, Tai Shogi is not the biggest Chess game to ever exist.  It used to be, until some documents were uncovered in 1997 with rules for a 16th-century Shogi variant called Taikyoku Shogi, or ‘Ultimate Shogi’.

This preposterous game is played on a 36×36 board of 1,296 squares.  Each player has an army of 402 pieces, and to play you must remember 253 distinct movement patterns.  Each side starts with a King and Crown Prince on the board, and a Drunk Elephant who can promote to Crown Prince — meaning you may have to capture three royal pieces to eventually win.

Unlike the other huge variants, in Tai Shogi promotion is once again by entering the enemy camp rather than by capture.  Each army contains a huge variety of pieces with whimsical names like the Running Bear, Vermillion Sparrow, Violent Ox, Enchanted Badger, and — my favourite — the Vertical Puppy.  If I ever play this game somehow, I’m going to devote my entire strategy toward devising a way to checkmate my opponent using the Vertical Puppy.

Amazingly, a real-life wooden set for Taikyoku Shogi was carved and used for a special segment on the Japanese variety show Fountain of Trivia back in 2004.  Two Shogi pros faced off in a game of Taikyoku Shogi, using a little reference book to help them remember how the pieces moved.  The game lasted 32 hours and 41 minutes, and ended in checkmate for the first player after 3,805 moves!

There’s a clip of the match on YouTube, unfortunately the quality isn’t great but the whole segment is there: https://www.youtube.com/watch?v=_c0Y26iTPSM

At the end of the match, the winning player says ‘I don’t want to do that again’; the loser says something hard to translate, but it’s kind of like ‘I have no regrets’, conveying the impression he doesn’t mind losing something so bizarre, and is mostly glad it’s over.

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A closer look at one player’s setup in Taikyoku Shogi — imagine trying to remember all 402 of these pieces!

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A fanmade version of Taikyoku Shogi — quite impressive!

 

Notes on the large Shogi variants

For much more detail on the Shogi variants, I recommend checking out this GeekList on Boardgamegeek.com from Shogi enthusiast The Player of Games that describes a large number of them.  Numerous resources are linked there, and I borrowed a bunch of the images in this post from there as the photos the author took of his sets are far better than any others I could find.  Many thanks to TPoG for taking the time to produce such crisp and high-resolution images of these great games!

Most importantly, TPoG’s list includes a detailed discussion of some discrepancies in the moves for certain pieces — the three main Edo Era sources for the larger games differ slightly in how they describe some moves.  For the most part these differences are very minor, and in games this size aren’t really going to have any influence at all on the overall play.

However, the recommended changes in that list for the upgraded forms of the Lion make much more sense than the currently-available moves in the English versions of these games.  They actually build on the Lion’s powers rather than weakening them.  For reasons of consistency I highly recommend using the updated moves suggested in that list when playing Dai Dai Shogi, Maka Dai Dai Shogi or Tai Shogi.

Where do I go from here?

Well, as you can see, Shogi offers a whole world of interesting games.  I wrote far too much here, and yet still didn’t cover anywhere near all the variants — there’s a number of smaller ones too, but I just love the big monster games.  If you fancy trying a variant of Shogi, and want to pick just one, I’d recommend Chu Shogi — it’s monstrous without being ponderous, and the Lion is such a creative and beautifully-balanced addition to the game.  Leaving aside my nerdy fascination with all things Shogi, it’s a genuinely delightful game.  Tori Shogi is also a great choice, as it’s small and easy to learn but still has tons of depth.

If you want to dive headfirst into one of the monster games, I highly recommend Maka Dai Dai Shogi.  It’s a fascinating game not just in terms of its unique play style and unusual pieces, but also because of its intriguing history and cultural relevance.  When playing this game you can feel that it could have been a ritual experience, a rumination on Buddhist thought as well as a battle playing out on a (huge) chessboard.  Sure, it’ll take awhile, and will require patience and dedication to get through a game — but those are quite Buddhist qualities, are they not?

Your best bet of course is to play modern Shogi — in my opinion it’s the finest version of Chess by quite some distance, and can easily support a lifetime of play and study.  There are numerous places these days to play online, like 81dojo  which is free, available in English and supports several variants as well.  Obviously modern Shogi has by far the largest playing community of any version of Shogi, and rightfully so — it strikes a balance between complexity and simplicity that’s hard to beat.

For a taste of Shogi, come on down to our Shogi event next month and get acquainted with the modern game!  I’m sure you’ll enjoy it, even if just as a peek into a corner of Japanese culture most of us never see.  For those of you who really take a fancy to the game, you’re welcome to join Shuzo and myself in our soon-to-be-launched Shogi club, which will meet regularly in Glasgow to play Shogi and learn about the game.

And, if you’re a weirdo like me who can easily spend all day playing games, join me for a game of Tori, Chu, Dai, Tenjiku or Maka Dai Dai Shogi!  Just make sure you free up your schedule first 🙂

 

 

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