Comments/Ratings for a Single Item

When I first saw this game, I didn't think much of it, since I was more focused on larger Shogi variants, especially Tenjiku Shogi. However, now I have a few games against Jocly under my belt, and wow, this game completely blew me away. It is an absolute joy to play, despite its size and complexity (which melts away after a couple games). However, it is not flawless.

The Lion-trading rules are a bit complex, and making the Lion contagious (Like Maka Dai Dai Shogi's Deva, Dark Spirit, and their promoted forms) would make the rule much simpler while also achieving the same effect. However, this isn't really much of a problem, and may in fact be the better choice.

The real problem that I have with this game is that modern "innovations" have made the game more complicated than it needs to be. The repetition rules are quite complex, so much so that most computer programs for Chu Shogi that I know don't implement them, which is a trait borrowed from Xiangqi. The King Baring rule is completely unnecessary, as it does not add anything to the game that the combined effects of the other rules do not achieve. There is no evidence that it existed in the Edo period, so I'm not sure why someone thought it would be a good idea to mention this.

However, despite these problems, Chu Shogi is still easily among the best games of its kind. If you like Chess variants, you should give it a try.

Chu Seireigi is an attempt to combine elements of Chu Shogi with the ruleset of modern Shogi. It also has the benefit of not needing any special rules to preserve its quality, fixing all the problems with the modern "innovations" for Chu Shogi that I mentioned above. Players are disincentivized from trading off the Lions in many cases because they would just go into the player's hands, making them even more dangerous. The repetition rule is simply that of Shogi (draw, except perpetual check loses), and the drops make King-baring extremely rare. However, this comes with the unfortunate downside of having to remove the multi-move and orthogonal step from the Lion's move, as otherwise, it would be too strong, even if only the multi-move was removed. To compensate for this, the Lion also moves as a Bishop (in effect making it a Bishop+Squirrel compound).

The repetition rule is a modern contamination by Xiangqi. In the historic rules repetition was forbidden, but it is likely that perpetual checking was forbidden even more: some of the historic mating problems would have fast parasitic solutions if you could force a win by perpetual checking. It is also not clear whether repetition of positions was strictly forbidden, or making the same move from an earlier occurring position was.

The baring rule is also a modern invention; there is no historic evidence that it existed in the Edo period.

The link section should mention that Chu Shogi is playable on https://lishogi.org now as well.

This looks good. You could remove the Side Movers as they make the game too defensive, and the Coppers that promote to them at the same time. Lances that promote to Great Tigers cover at least the same movement capability as Side Movers.

The majority of the promotions won't be the same as in Chu Shogi, and this includes the Copper Generals, which would promote to a Silver General that can also jump to the second square orthogonally sideways or forward, or diagonally forward.

As it is now, the Side and Vertical movers can't move backward at all to try and ensure that they don't add too much to defense, but the sideways slide of the side movers may indeed be a problem. The question now is, what to replace them with?

The Drunk Elephant could also be removed as its promotion to Crown Prince would drag the game out needlessly.

I wasn't planning on having a piece that promoted to another royal, I can simply have the elephant (or its equivalent) not promote to begin with or make its promotion non-royal.

Knights could move to where the Coppers are, allowing them to move freely in the opening.

There is a defender (the Donkey). It works together with the Knight to protect the outer pawns from a distance, hence why the Knight is placed where it is. Like the current Side and Vertical Movers, the Donkey one of the pieces with no match in the Mnemonic piece directory for its Dai Seireigi move, and instead is being approximated, hence why you didn't see it initially.

This looks good. You could remove the Side Movers as they make the game too defensive, and the Coppers that promote to them at the same time. Lances that promote to Great Tigers cover at least the same movement capability as Side Movers.

Knights could move to where the Coppers are, allowing them to move freely in the opening.

The Drunk Elephant could also be removed as its promotion to Crown Prince would drag the game out needlessly.

A defender is needed for the second pawn (in particular) and second-to-last pawn. The Dragon Horse can capture and promote without being captured otherwise.

I'm guessing that's what happens when you use the drop rule with a game that wasn't designed for it. I'm attempting to solve this in Dai Seireigi by using the same forward bias found in regular Shogi.

Here's a prototype of what I have so far (You may need to view this comment by itself for the diagram to show, and some of the mnemonics are close approximations of the actual piece). Only the eight most valuable pieces are not subject to this forward bias, and the Falcon and Eagle (promoted Horse and Dragon) will be subject to it as well.

The promotions are not included, as I haven't sorted that out yet, except that the King, Lion, and Queen do not promote, pieces found in normal Seireigi promote as they do in that game, and that I plan on adding Korean-style hopping move (without restrictions on what it can do) for a few of these promotions.

Indeed anti-trading rules would seem useless for such games.

People have tried playing Chu Shogi with drops, but from what I heard this led to most of the board and pieces remaining completely untouched, with only activity in a small central corridor.

I am thinking about doing something similar with a game called Dai Seireigi, which is basically Chu Shogi, but with drops and an altered piece/moveset roster to account for the drop rule. This includes replacing the Lion power with a "hit-and-run" ability that allows a piece to move or capture on a square and then move without capturing to a square adjacent to . This allows pieces with the ability to capture a piece in a certain direction and then maneuver into place to check the enemy King, while also not being too overpowered for the drop rule.

The Dai Seireigi Lion would have the hit-and-run ability in all directions, and a two-step area move, similar to that of the Tenjiku Shogi TSA Lion Hawk, but without the ability to return to its starting square (KmcamKaK).

However, I have an important question regarding anti-trading rules. Since in a game with drops no piece ever goes entirely out of play, would you need an anti-trading rule in such a game?

Really thanks !! 8ㅁ8

Sure, you are welcome to use them. As far as I am concerned, they are public domain. I am happy you like them.

Thanks for the reply!

This may be a rude question, so I apologize in advance

I would like to ask if I can use your geometric pieces

I think those geometric pieces are the most intuitive icons I've seen so far, yet they provide a familiar accessibility to beginners

Of course if I use it I will specify that it is made by you

If this was a burdensome question, I apologize again. Is it ok if I use it?

I did.

Can anyone tell me who made those geometric icons?

(The interactive diagram in the main text)

Yes, HaChu was written by me, and yes, I am in practice the only WinBoard/XBoard developer. PM on WinBoard forum is not really a good way to reach me, as my inbox there is overflowing. TalkChess.com would be a better forum, but for private communication e-mail would be preferable. However, I usually prefer public over private communication; most things that are discussed tend to be useful for others as well.

The mnemonic pieces were indeed conceived from the wish to be able to play these horrendously large games with virtually no learning at all, because 95% of the piece symbols unambiguously indicates its move. So you only have to worry about a hand-full of (often very special and very powerful) pieces, such as Lions, Teaching Kings and Fire Demons.

It is great that you are working on a replacement for the 81Doju Chu-Shogi website. In practice it might be difficult to get the population of that website to migrate to yours, through, no matter how nice it is. Especially the Japanese players. Setting up a new site also means the loss of the database of all games that have been played so far. Perhaps it would have a better chance of success if you would just build a new client for the existing 81Dojo Chu server.

@Muller

Thank you very much for SVG pics! :) They're excellent!

In general we're going to popularize Chu Shogi and (I hope) the others Large-board shogi variants as well.

Mnemonic SVG images are extremely helpful for introducting the game for beginners and others who is afraid of japanese hieroghyphes. Especially including into account that Chu Shogi itself includes comparativelly so much pieces with different variants of move, that it's difficult to remember them in case you don't love it initially. What to tell about much larger variants of shogi with a much complicated move rules.

If we combine mnemonic pics with a pleasant (a bit beautiful) interface, move tips and learning for new players, add HaChu engine for playing with computer (I guess, your work?), and also add possibility to play with another peoples over network (planned in nearest future) - we'll get the platform that actually can be distributed around the world in a much easier way, than before.

For example, when 81dojo came into world, it popularized shogi around the world quicker. The analogue for the Chu Shogi - the Chu-Shogi Renmei 81client had a similar impact, but it still contains hieroglyphes (however it still has a nice interface through). For now Chu-Shogi Renmei 81client is under danger to be unavailable because of outdating of Flash Player technology. If after end of 2020 Flash Player apps will be actually blocked (forcefully), then the remaining variants to play over Internet would be a few. Maybe ChuDo will be one of most comfortable of them. That is the point - the more comfort - the more people coming, as there is easier to entry into the game.

I have registered on WinBoard forum, I'll take pleasure to contact you there via PM or any another way. If I understand correct, you're the only (or main) developer of WinBoard/XBoard programs, are you?

@Alex - The mnemonic pics here were copied from WinBoard by taking screenshots, where I used a general-purpose drawing program to make the background transparent. WinBoard creates those images on-the fly, from components that represent the move in one direction (but i a way depending on the range in adjacent directions), plus a central dot. In order to draw an edge around that for the outline pieces, it creates a black image first, and overlays it with a slightly smaller white image, so that a black outline remains. The largest size is 33x33, though, and the images are not anti-aliased.

I remember having made a set of SVG images for each of the individual pieces, for XBoard, though. I am pretty sure this includes all the Chu-Shogi pieces, and probably also the Wa-Shogi pieces. I would have to dig that up; I could not find it on my website.

Interesting that there now is a new Chu-Shogi engine. How strong is it, compared to HaChu?

As to larger variants: I have a pretty strong engine for Tenjiku Shogi. (Not yet released; I am still planning to do that.)

I am not on Facebook.

[Edit] Oh, I see. The engine actually is HaChu. It is only the interface that is new.

[Edit2] I found the SVG pieces, and uploaded the whole project to http://hgm.nubati.net/Mnemonic-S.tar.gz .

Hello, H.G. Muller!

So, if I understand right, you weren't drawing it by yourself?

Recently one man named Joe Henbethydd have developed a Chu Shogi program with a pleasant interface. I took participation in its localization to English. You can try it yourself here http://anubhuuti.com/chudo/

As I understand, he is planning include multiplayer game over network in future, also I hope, he is planning include another Large-boards variants of shogi like Maka Dai Dai Shogi etc. But it is not exact. Time will tell.

For popularization purposes of Chu Shogi there is a nice idea to use mnemonic pictures representing piece's moves. I really like it, and I use it as my memory sheets, and also I use it when teaching peoples how to play Chu Shogi.

It is nice if we would integrate such mnemonic pics into ChuDo program of Joe Henbethydd, but unfortunately, the pics are somebit a low quality (I mean low resolution). It is nice, if we have at least 200x200 sized images, or (which is better) vector images.

At the moment we don't have any artist which could draw for us such image assets.

So the question is - where did you actually get the mnemonic pics? Have you drawn them by yourself, or you just used already existing images, which is located in the link you provided?

Anyway nice to meet you, and hope we shall some time play Chu Shogi or another Large-board variant of shogi.

P.S. By the way, do you have any page on Facebook? There is a Chu Shogi group, maybe we can find each another there and write one to another sometimes?

Sincerelly yours Alex Trick

They are in graphicsDir=/membergraphics/MSdaishogi/ .

Just go to the web page http://chessvariants.com/membergraphics/MSdaishogi to see how they are named.

If you are okay, Can i know where and how did you use the mnemonic characters?

Using my (pre-adjustment) piece value table, under early middlegame, the value ranges given are as follows:

• Pawn -2.5/4/6 (Tokin 9/9.5/10)
• Go-between 8/8.5/10
• Bronze 6/8/9
• Silver 8.5/10.5/11
• Leopard 9.5/10.5/11
• Lance 14.5/16 (White Horse 25/26/27)
• Kirin 18/19/20
• Bishop 24/26/29

Then I adjust the values using things I know about the position, which can easily swing them a further 20% for ranged pieces, 40% for small pieces, and 200% for individual pawns.

I wrote the table to suit my personal style, at the behest of one Andrej Trauner, so it may not be applicable to others. I believe it a safe assumption that my table is the most thorough estimate of chu shogi piece values in existence, especially when combined with the list of adjustments, which only exists in my head.

I don't put too much weight on material advantage when playing. It only accounts for roughly 35% of my evaluation, compared to about 60% for purely positional considerations.

Well, it estimates about 450 for both Kirin and Lance! (to compare: 480 for Bishop.) It differs a bit each time, as the estimation process involves random sampling.

It takes many tempi to attempt to promote a Lance. Edge attacks have never been my favorite, so I haven't had much experience in playing for such promotions, until very late in games. However, based off opponents who have tried to move along the edge files, and my defense against such attacks, I have concluded that early edge pushes require at least 20 tempi of preparation to be mildly successsful, against someone who is not exactly interested in the same. A player can comfortably defend, at least for a while, but the edge file attacker can get through at least one promotion exchange if they put enough in it, this usually being some exchange like Dragon-promoting for Rook. A player must be particularly careless to allow a Lance to promote safely and flee.

Overall, I don't rate Lances that highly, perhaps around the same as a Kirin.

Yes, of course it is very weak. It searches only 2 ply, and that isn't even enough to see a mate-in-1 threat coming. You can switch it to 3 ply, but in a game as large as Chu Shogi that would probably already make it think too long. This is JavaScript, not a C program!

I am sure I could make a search that plays much stronger with the same number of nodes. I put this one together in two days. But that is not meant as an excuse: I intend this thing to be weak.  It is meant to be a demo for people that have never played the game before, and visit the page the diagram is on to learn about its rules, so they can have a sparring partner to get a whif of how the rules work out in practice.

Also note that it doesn't use any variant-specific knowledge other than the rules. It has to guess the piece values itself, and I am amazed of how reasonable these guesses appear to be. I made a version that also tries to weight in promotability, by making some weighted average of the values of base piece and promoted form, where the weight of the latter increases with the ease of its promotion and the relative gain of intrinsic value. That also looks reasonable, except that the current algorithm then puts an unexpectedly high value on the Lance. It seems this has the most favorable prospects for promotion, so that it assumes you would do your best to preserve it until it can actually promote, rather than lose it in tactics to clear the way for others. (Of course it doesn't realize the Lance is file bound, so that you really don't have much choice in the matter...). But now that I think about it, perhaps this is not such a silly thought. The Lance itself is pretty useless in combat, can reach the zone in a single move when the time comes, and a White Horse is one of the more valuable pieces.

So, I switched to Firefox. It appears to be working better now. Still very weak AI

I thought the AI would be easy picking but it is not :)!

Capture bridges now also work. The anti-trading rules in Chu Shogi are so complex because they are applied to a piece capable of double capture, so that a trade could be accompanied by a sizable material gain, and they did not want to outlaw that. The same could in principle happen when several piece types of unequal value are subject to this rule. (As is the case in Tengu Dai Shogi, where Lion and Lion Dog can also not capture each other when they are protected.)

I solved it by specifying a value threshold, and when the combined gain of the capture is larger than the value of the capturer plus this threshold it can be made safely. Because the piece values are only known to the diagram, the option to specify this is tradeThreshold=N, where N is the number of the most-valuable piece that can not act as a capture bridge. So in this case I specified N=2, as the GB was defined as the second piece.

This appears to work, as can be easily tested by dragging a white Lion to i6 and a black one to g7, switch the AI on, and then drag various white pieces to h6 (and then take back 2 moves for the next try). For every piece black should then play Lnxh6xi6, except for P and GB, where it will play something else.

For me it plays BT-g10 instead of Lnxe7. Your browser must be using an old cached script.

BTW, I sort of patched the counter-strike problem now, by paying more attention to what the lastest move was when invoking the AI, and making it aware of a preceding non-Lion x Lion when I set it thinking. This too isn't perfect yet. (It would miss a locust capture of the Lion by a Falcon or Eagle.) But for now it should do.

The point is that I want to replace the entire old move-entry system of the diagram, which had a move generator that directly highlighted squares, in interaction with what already had been clicked, by one based on the new move generator in the AI. The latter just generates a list of all moves, complete with all side effects. And because it can search ahead, it will be able to judge even the more complex legality conditions perfectly. The highlighting during move entry should then be based on that list, and the moves would automaticaly be in AI format, so that they can be fed back into it when it goes thinking for a reply. So it would be a bit of a waste to spend too much time patching up the old system for better interaction with the AI.

I had managed to clear the cache but the error still goes. I use microsoft edge.

Same with me.

1. Nf5 Cd11 2. Ne7 Ci11 3. Nxd8xe7 Ng8 4. h5 Nxe7

Wow cool thing supporting the imitator. I remember earlier versions were not able. Does the AI work also with it? This could sound silly, but random initial positions are supported?

Well, for me it doesn't capture the Lion, after these moves. I don't know what browser you are using, but on FireFox I can clear the cache by keeping Shift pressed during the page reload.

The diagram already supports a Betza notation for a Joker (I for Imitator). See the 'Betza sandbox' comment on Betza notation.

And by the way, talking about previous moves, is there a way they will be taken into account as I am thinking about the joker in my apothecary chess game.

The game started from regular initial position and it went like this : 1. Ng5 Cd11 2. e5 Ci11 3. j5 Nf8 4. h5 Tg10 5. Ng6 Nxg6 . I'm not sure what needs refreshing.

That is not enough information to set up the position. Can you post the game that it prints below the diagram, up to the position where it happened?

And did you make sure your browser cache was refreshed, so that you are using the updated diagram script, rather than an old cached one? (BTW, counter-strike is still a problem, because the AI does not take prior moves into account. So it wouldn't know that non-Lion x Lion took place.)

@HG,

Hello,

I had just tried it and my advanced lyon defended by the DH got captured by the AI. I then tried it again. It seems to happend to player's lyon on 6th rank once the second dk pawn got moved. Maybe if you try reproducing such a position you may find the bug!...

The AI of the diagram now also has a vague notion of the Lion anti-trading rules. It isn't perfect yet, because it does not apply the rule for 'bridge capture' yet; you can just generally forbid capture of protected pieces of a certain type. It also doesn't limit it to distant captures, but I guess that only means it unjustly forbids moves that you would never want to make anyway.

Good job, Adam!...

Excellent, passed all my tests. Thanks again! I will be using this preset from now on.

You can find it here: https://www.chessvariants.com/play/pbm/play.php?game=Chu+Shogi&settings=chu

Would you share the link to your newest preset, Adam?

The preset has been posted, and everything seems to be working properly.

Everything should be in order apart from the restrictions against indirect trading of Lions (and the repetition rules, which i won't implement because it's way too complex). All I really did was copy the Tenjiku Shogi preset's code to this preset and modified the code to suit the needs of the Chu Shogi preset.

Just to make perfectly clear: any piece may capture a Lion, that has captured a Lion on the previous turn. Restrictions ONLY apply after a non-Lion captures a lion. This rule has been incorrectly written in some parts of this site, which I have complained about before. And thanks for working on a new preset, Adam ^^

I will test to make sure everything else is in order

In an engine I solve this by making a Lion that captured a Lion (from a distance, etc.)  a temporary absolute royal for one turn. Then playing Ln x protected Ln is considered exposing yourself to check. (In my Crazyhouse engine I do something similar to enforce the ban on castling through check: castling initially ends up with the Rook replaced by a second King. After move generation of the opponent (which would detect the King capture) I then replace that by the Rook it should be. After Other x Lion I make the opponent's Lion iron for one move.

All you need is the concept of 'temporary promotion', piece types that at the beginning of their own turn revert to the unpromoted form. And then have some extra types that are royal and iron.

Btw, note that the counter-strike rule on Lions does not hold when the two Lions are captured on the same square. If a Kirin captures a Lion and promotes in that same move (to Lion), it is allowed to recapture it.

A player may have 2 Lions as a Kirin may be promotted to a Lion

As I understand these, a lion may not capture a protected lion, and a piece may not capture a lion if one was captured on the previous move. While the second rule applies only to non-lions, it is applicable only in a situation in which a player no longer has a lion. So, that detail of the rule can be safely ignored, and it can be applied to any piece.

I am nearly finished making a Game Courier preset that enforces the rules of this game and displays legal moves. However, the Lion trading rules haven't been implemented yet because they are giving me some problems. Any ideas on how to solve this?

You can find the preset here: https://www.chessvariants.com/play/pbm/play.php?game=Chu+Shogi&settings=chu

No, those discussions are about the interactive diagrams.

Is there a new enforcing preset I'm unware of? 

When I try to promote a Dragon King, it promotes to a Tokin instead of a Soaring Eagle. However, this can be easily fixed by making the King the last piece and changing the parameters accordingly.

Ok, HG,  thanks!

Getting a Lion out early is OK; it is impervious to stepper attack by its igui capability, and can easily withdraw when chased by sliders because of its jumping ability. And if the opponent develops his Lion, you often have no other way to keep it at bay than opposing it with your own Lion.

But suppose your opponent will keep his sliders safely behind his Pawn wall, and advances his Copper, Silver and Leopard while you are dancing around with your sliders. No matter how fast you develop your sliders, they won't be able to breach the Pawn wall, as this is well protected by the opponent's sliders without him having to spend many moves: his sliders start there. At some point the Silvers and Coppers stream out through the occasional hole in the Pawn wall, and will start forking your valuable sliders, which are trapped in the narrow area between the Pawn walls (usually both sides advance all their Pawns one step without opening up large holes, to allow the Side Movers to cover the original Pawn rank). You will get slaughtered.

Sliders are very valuable in Chu Shogi, because they promote easily in the end-game. Promoting steppers, OTOH is very difficult: they need to approach from afar, and by the time they reach the zone the opponent will oppose them with his steppers, needing far fewer moves to do that. And you have to overcome the extra defense provided by his Side Movers; you cannot neutralize those with your own Side Movers. Basically you can only promote steppers that are left over when all stepper material of the opponent has been traded away. So if there is an imbalance where you have steppers, and the opponent tactically equivalent sliders, and the potential promotion gain is the same, you are toast: he will promote all his sliders long before you promote your first stepper, and this will put you at such a tactical disadvantage that you will not have any steppers left by the time the opponent has not enough material left to prevent them from entering the zone.

In warfare one should never expose one's artillery to infantry attack!

About the strategy part of the article.

From the games I had played against user Dax00 it seems to me the advices here are not optimal although wikipedia states roughly the same things regarding the early moving up of steppers.

In our games dax00 has taught me to early lyon jump in front very early (the latest at turn 3) and then the stronger pieces take relevant forward positions until it becomes worthless for them to keep dancing around, and only then steppers (and maybe phoenix) kick in slowly but surely as the strong pieces are stuck in their duties :)!

What am I missing?

I have not really looked at those problems to see if I could find an easy flaw since I first analyzed them, and have been busy with other projects since.It seems a daunting task to figure out if the lack of a solution is due to a plausible oversight of the composer, and what he overlooked. I am not even sure how one would have to approach that problem. The computer just concludes whether there is a mate or not. It doesn't know the concept of 'nearly mate'. Because all the moves are checks it is not uncommon in problems that do have a solution that there is only a single legal move for gote in some positions, or only a single move that does not get him mated very quickly. So having only a single move to escape the mate in some variation doesn't really indicate the composer must have overlooked that move. (Ignoring the problem that the computer usually does not know there is only one refutation to the mate attempt, as it doesn't search any alternative moves once it finds the refutation. This could be solved by altering the program to require at least two refutations in each position, at the expense of driving the solution time up by a factor of 2^N for a mate in N full moves.)

It really requires human judgement to identify a move as a plausible candidate for being overlooked.

Perhaps the following would work: equip the program with a 'conditional exclude-move' option, through which you could tell it: in this position, you must consider that particular move as illegal. You could then start running the engine on the the flawed problem; it will find a principal variation that keeps up the checking as long as possible, but eventually it will run out of checks. You can then try to 'repair' the problem by 'outlawing' the gote moves in this PV one by one, starting at the end, and try to solve the problem for that case. If the outlawed move was the only move that escaped mate, the problem would then have a solotion, and the defensive move could have been the one overlooked by the composer. If the problem is still flawed, because gote has an alternative escape, we probably are already in a position that was never intended to occur.

@Dr Muller: You had mentioned that you had analyzed the D document of historic chu shogi problems in MSM, had reserved the results of your analysis, and had concluded that 18 were proven flawed.  I wonder if you had reached a conclusion about the 18 like one that Mr Hodges proposed about the D document generally, that necessary pieces possibly had been omitted or erroneous pieces introduced into the diagram to act as a security device against plagiarism.  I read your suggested corrections to problems in the other 3 collections; I do not ask you to divulge more than you want about D, only to ask if your research suggested that the flawed problems might be fixed by the removal, change, or addition of pieces to the diagram.  Kind regards!

Only Pawn, Leopard and promoted Leopard cannot not force checkmate on a bare King. Many of the weak pieces lack mating potential, but against a bare King they should be easy to promote, and all promoted types except Bishop have mating potential. Because they virtually all have at least one orthogonal sliding move, and can move perpendicularly to that. That is all that is required, and makes the mate in fact quite easy (so that last century even a mechanical machine was built to do it!). The other exceptions are +P and +DE. As it turns out, Gold has no mating potential on 12x12 (it stops at 11x11), but DE and +DE still have (up to 14x14, IIRC, which would affect Dai Shogi). A Blind Tiger that cannot seek shelter with its King can sometimes be chased by the bare King to its back-rank, and get lost there. And Pawns approached from the front are doomed too, if the bare King gets there before yours.

The only pair of pieces without mating potential is a pair of +FL on the same 'square shade'. Provided none of them is trapped, which for two Pawns far away from each other can be a problem.

Dr Muller, you mention the bare king rule as used by the Nihon Chu Shogi Renmei, but I have to wonder if your computer analysis has revealed what pieces singly or in combination are sufficient to force or at least deliver checkmate on a bare king in chu shogi.

These are mere presets that do not include settings files. I edited the HTML forms for the Chu Shogi presets to use FEN code that has not been URL encoded.

Hi,

I don't know if anyone has mentioned this yet, but the chu shogi preset is not working; I had a look, and the { } 's in the FEN code seem to have been replaced with their charachter codes, and when you click 'menu' from an already active game it seems to use the chess FEN code. I can't edit it because I didn't make it and the FEN code can't be changed via customize.

Would someone be able to check it out?

Thanks in advance!

sxg

Here's a set I made earlier so if people are looking for cheap ways to make a chu shogi set here's an idea. I drew the board but you can also use a 13x13 go board too. The counters cost me about £1.50? And I just wrote on them with sharpie.

If you want to have the images hosted here (if they are just on your computer, not on the web yet and so have no URL), send them to me and I'll put them into the folders for the respective games.  (The text editor doesn't support uploading of images, AFAIK)

Click on the image button and enter an URL to the image. It's to the right of the flag (Anchor button) and to the left of the graph (Table button) in the right center part of the top row. Or go to Source mode and directly enter HTML in the form of

<IMG SRC="image-url">

Oh it looked fine from my iPad? I pasted a photo into the comment. Is there a better way to do it?

It looks like you used a fake URL for your image. It literally says "fake-url" in it.

Here's a set I made earlier so if people are looking for cheap ways to make a chi shogi set here's an idea. I drew the board but you can also use a 13x13 go board too. The counters cost me about £1.50? And I just wrote on them with sharpie.

The rule does not apply to your case for multiple reasons:

• It specifies what happens after a non-Lion captured a Lion, while your case starts with a Lion capturing a Lion
• The rule applies to what happens when the Lions are captured on different squares, while in your case the two Lions are captured on the same square.

So neither the protected-distant-Lion nor the counter-strike rule apply to this case, which by default means the recapture is allowed. There even is a special Japanese term for this, which translates as 'beating/shooting the Lion'.

BTW, the addition 'on another square' is there to handle the unique case of a Kirin (a non-Lion) capturing a Lion and promoting, so that the recapture now hits a Lion too. Recapture of this Lion would be allowed, while a counter-strike against a Lion elsewhere with a non-Lion would be forbidden.

Ok, next question:

If a Lion captures the opposing protected Lion by means of capturing a second piece first, is it then permissible to recapture the Lion, or does this rule prevent it?

A non-Lion cannot capture a Lion when on the previous turn a Lion was captured by a non-Lion on another square.

It sounds like this rule prevents it, but that seems crazy. 

Yes,it is always allowed to capture an adjacent Lion. Even if it means your Lion can be recaptured afterwards.(Which you usually of course can and want to avoid.) In this case the recapture would also be legal.

Can someone please help me with a question regarding this rule?  I need an answer for a game in progress...

A Lion cannot capture a Lion if that would expose it to recapture in the next turn, as if it had become an absolute royal for one turn. ('protected')

My question is this: can a Lion make a 2-step move in which he captures the other Lion (which is protected!) with the first step, and then move to safety with the second step?

Thanks!

I put together my own Chu set based on the mnemonic pieces, by simply cutting their shapes from stickers, and stick those on Draughts chips. Two Draughts sets of 2 x twenty 35mm chips were used for the (32) pieces, while a set of smaller (29mm) chips was used for the Pawns and Go Betweens (14 chips used). The required board is 42 x 42 cm, and was simply drawn on four sheets of A4 paper.

@Bukovski:

Yes, I used my Chu Shogi engine to solve all 224 problems of the A-D series,or prove no solution exists. Series C and D were different from A and B in the sense that the historic documents from which they came containedno solutions. So all problems that were solved when the MSM was published were solved in recent times, and many were still unsolved. Of the latter, 14 problems of the D series could be solved, while18 were proven flawed.

So far I did not put the results of the D series on-line, to keep open the possibility to use them in contests. (I thought I had done the same with the C series,but apparently not.)

Dr Muller, I read your very intriguing presentations of errata in the tsumechushogi problems from collections A, B, and C published in Middle Shogi Manual.  I have to wonder whether there are errata in collection D that your analysis has revealed and whether you would think such fine studies worthy to add to CVP.

Yonin Shogi is a 4-player variant of modern Shogi, so I suppose you mean a 4-player variant of Chu Shogi here.

I don't think that this would be a viable game. Multi-player versions of Chess are troublesome, because there is every incentive to not get engaged in battle: even if your tactics gain material compared to your victim, you in general lose compared to the idle by-standers. This does no longer apply when winning a battle actually gains you someting on an absolute scale, as it does in games where captured pieces can be dropped as your own.

So it is the drops that make Yonin Shogi an interesting game. And Chu Shogi has no drops. Of course you could allow drops in the hypothetical Yonin Chu Shogi, but Chu Shogi with drops is in itself troublesome, because of the very wide strength range of the pieces. I guess this could be fixed too, but if you change too much you will get a game that has so little resemblance to Chu Shogi that it would only be confusing to call it Yonin Chu Shogi.

Well, I have given the reference to the hard evidence: the Middle Shogi Manual compiled by George Hodges in collaboration with the research group at Kyoto. It contains the references to the historic sources on which it bases its conclusions, which I have paraphrased here. The sources themselves are of course all in (archaic) Japanese, which I cannot read at all. But I have no reason to doubt Japanese academic research on this. 

In fact I have a lot more confidence in Japanese academic research than in some western clown that 'just knows things' without being able to tell where this knowledge comes from, and then blames others for his ignorance. But everyone can of course decide for himselve whether he rather believes a Japanese history professor or a bragging westerner, on matters of japanese history.

And the 9x9 game of course became only popular after the introduction of drops. That transformed it from the boring Shatranj-like game to the fast and exciting game Shogi is today.

BTW, just looking at the game suggests Sho Shogi would not stand a chance to rival Chu in popularity. Compared to Chu it is as dull as Shatranj is compared to modern Chess.

This is a subjective claim, and Spengler Georg is right to criticize you for it. Saying something like this just doesn't prove your point. Besides that, the complexity of the game is a strike against it. Popularity is about numbers, and more people are likely to play a game in greater numbers if it is easier to learn.

In addition all historic variants seem to be based on Chu Shogi, and evolved towards larger size. If people would have thought the smaller game was better, you would have expected them to make variants based on Sho.

This is a more compelling point, though it will require some demonstration, and it still doesn't prove that Chu Shogi was more popular. Furthermore, modern Shogi is apparently a variant of Sho Shogi, and that became the most popular Shogi variant in modern times.

If Sho Shogi was more popular, then it followed the same trend seen in China, Korea, and the west of the most popular variant being a game of around the same size with similar pieces, and it better accounts for modern Shogi being more popular today than Chu Shogi is. But if Chu Shogi was the more popular game, it is the exception to the rule, and we are left wondering why its popularity declined in favor of a very different game. So it looks like the default position is that Sho Shogi was the more popular game, and if you want to claim that Chu Shogi was more popular, you will need hard evidence to back this up.

No I do not know any game scores of standard Shogi prior to the 19th century. And that's quite strange.

You must understand, true, I am not really sure about the situation in the Heian and Kamakura period. But in the Edo era, from the end of the 16th century on, if somebody said "Shogi" he meant the game on 9x9 squares. If he meant another variant, he had to specify. It was the most prestigious game in Japan after Go, which was - of course - the game of games. Shogi - the 9x9 game  - was promoted by the Shogunate, the government. Like in Go, the official title of Meijin for the best Shogi player was established and the annual castle tournaments were held, in the presence of the shogun or even the emperor, I'm not sure. At this time the names of the first great players are known. They all played the 9x9 game, not the bigger variants.

My sources? Are you kidding? That's so basic knowledge, you cannot dive into the history of Shogi for one afternoon without knowing that! 

And now to your statement about Standard Shogi and Shatranj being "dull" games and that just having a "look at the game" of Chu Shogi  suggests Sho Shogi would not stand a chance to rival Chu in popularity." and so on...

Now I have NO opinion at all which one is the "better" game. But you have disqualified yourself so much stating such a nonsense, that I really think that you do not know ANYTHING about what you are talking and just arbitrarily pick it from the web, and actually I do not feel like replying to you any more. Sorry, bro.

> So from which time are the first extant Sho Shogi game scores? Do you know that?

No, do you? You still haven't told me your sources.

BTW, just looking at the game suggests Sho Shogi would not stand a chance to rival Chu in popularity. Compared to Chu it is as dull as Shatranj is compared to modern Chess. In addition all historic variants seem to be based on Chu Shogi, and evolved towards larger size. If people would have thought the smaller game was better, you would have expected them to make variants based on Sho.

I believe you that they are actually played games. But you probably know that most of the extant game scores of European chess prior to the 19th century are composed games, especially in handbooks written to teach the game (for example ALL games of Greco are compositions). Also the oldest extant game scores of Chinese Chess are from such handbooks and are assumed to be compositions. So my assumption was not THAT farfetched. I do not know though if this "strange hobby" as you call it was common in Japan also.

And again, I never denied that Chu Shogi was a popular game. But I'm still not convinced that it ever was more popular than the smaller one.

So from which time are the first extant Sho Shogi game scores? Do you know that?

The MSM doesn't mention they are compositions. Why would anyone compose complete games? And even if they were, because people in those days would have such a strange hobby, it doesn't seem to make it less significant they composed Chu rather than Sho games, instead of playing them.

The MSM further states: "By the time of the Northern and Southern Courts period in Japan (1336-1392), Middle Shogi, played on a
board with 12 squares each way and with 46 pieces on each side, had evolved. In subsequent years it
enjoyed considerable popularity and our first clear record of the game dates from 1350." 'Record' here must not mean 'recorded game', but just a reference specific enough to recognize it unambiguously as Chu rather than Sho or Dai Shogi.

First published description of moves and rules is claimed to be the book "Aro Kassen Monogatari", volume 4, by prime minister Ichijo Kanera, dated 1476.

I was referring to the games Mori-Fukui, Kondo-Konishi and the handicap games Kuri-Masuda, Kuri-Sawada, and Mori-Matsumoto (2x). These are recorded in a manuscript from 1778, but it does not say when the games were played. The 50 mating problems by Ito Sokan I were published in the Chu Shogi Zushiki from 1697AD.

Do you mean the game scores of Yamagata? But they are composed games, aren't they? The first scores of really played games i know are from the early 20th century, but i don't remember where i have that from.

Do you know the earliest game scores of Standard Shogi? I don't!

If that's the Manual written by Hodges, I do know it. And you are RIGHT when you say it is first mentioned 100 years EARLIER than I claimed. I apologize. That makes it still younger than Sho and Dai Shogi EXCEPT when you argue that the Heian Dai Shogi was really a kind of Chu Shogi and The later Dai Shogi was the novelty. Dunno, you tell me!

But that the Yamashina family had a faible for Chu Shogi is meagre evidence for Chu Shogi ever being more popular than the smaller variant. On the other hand  the carpenter Minase Kanenari tell us  that between 1590 and 1602 he produced 618 sets for Sho Shog but only 106 sets for Chu Shogi (that's from the web). That also doesn't prove very much. Or does it? But I admit, I just thought that it was commonly accepted among scholars that at least in the 16th century and later Sho Shogi was dominant, and for earlier times we lack proper information. I never claimed Chu Shogi was not a popular game. Just that Sho shogi was more so.

I think when Hodges states, that Chu Shogi was the more popular game in the Kamakura period he overstretches the (few)sources we have about the game in this time. Historians do that very often. You should always reckon with that and being published by a University unfortunally does not prevent them from doing so. 

That the first tsumes and game scores come from Chu- rather than Sho Shogi I really doubt. But i cannot argue against, for I'm on holydays and the web is a very bad source for chess history. If it is right I would be very surprised.

I don't know where you got that from. According to my information, Chu Shogi was already mentioned in manuscripts dated as early as 1350AD. A diary entry from 1424AD mentions a Shogi match played in front of the emperor, where one of the players was handicapped by a Free King. So that was certainly not referring to Sho Shogi. It was apparently considered so evident that 'Shogi' would mean Chu Shogi that the qualification 'Chu' was omitted. Tsume problems dating from 1675AD, 1697AD and 1746AD are all Chu Shogi problems; no historic problems or game records from Sho Shogi are known from that period or earlier.

All this is described in the Middle Shogi Manual, which was compiled in cooperation with the research group on the history of Shogi at the University of Kyoto. What are your sources?

Chu Shogi has never been "the dominant form of chess in Japan", let alone "for centuries". This is perhaps a mistake caused by confusion with Sho Shogi (Small Shogi), the 16th century name for the predecessor  of Modern Standard Shogi (still without drops), to distinguish it from Dai Shogi (Great Shogi) and Chu Shogi (Middle Shogi). These larger games were popular, but Sho Shogi was the dominant game, even before the introduction of drop rules. Also Chu Shogi is the youngest of the three (15th century), it didn't even have the time to be dominant for centuries, for at the beginning of the Edo period (around 1600)Standard Shogi, promoted by the shogunate, began to oust the larger forms, even though many large variants were invented (and certainly played) at this time

I have a question for Adrian King.
I hope he reads here.

On Roger Hare's page, you are credited for the promotion rule, "if one of your pieces does not promote on the turn on which it enters the promotion zone, then that piece may not promote on your next turn unless it makes a capture on that turn. On subsequent turns, however, the same piece may promote whether it makes a capture or not, provided that it makes a move partly or entirely within the promotion zone".

I would be interested in knowing the origin of this rule, in particular the idea that promotability on non-capture would regenerate after ONE TURN. This is different from the rule described in George Hodges' Middle Shogi Manual, which states that such promotability only regenerates by MOVING THAT PIECE. This again is different from the current rules of the Japanese Chu-Shogi Renmei, which specify that the piece would have to leave the zone first. (In other words, non-captures can only promote when they enter the zone from the outside; moves entirely in the zone or leaving it can promote only if they are captures.)

So it seems there are three different versions of the promotion rules for the historic game.

This is indeed an interesting 11x11 variant, which at first glance seems a cross between Sho Shogi (9x9) and Chu Shogi (12x12). It shrinks the board compared to Chu Shogi by eliminating the duplicats of Bishop, Rook, Horse and Dragon, and having only one of these each.

On closer inspection there are quite some extra differences, though. The Ferocious Leopards of Chu are replaced by (Shogi) Knights from Sho Shogi, which then promote to FL. The Pawns are really 3 different kind of Pawns, the ordinary kind that promotes to Gold, but also those that promote to Silver or Copper. Gold promotes to Bishop rather than Rook.

There also seem to be differences in the way pieces move. The Blind Tiger seems to move like an inverted Silver (not sure if it is still called a Blind Tiger; my reading of the kanji is not that good), and their promoted form ('Flying Stag') does lack the sW moves. Also the pieces to which Dragon Horse and Dragon King promote (Horned Falcon and Soaring Eagle in Chu) now move different, and seem to have the double-move sting in 4 directions in stead of 1 or 2 directions, respectively.

The Lion does not seem to be a Chu-Shogi Lion, but a piece with a 'sting' in 8 directions, which promotes to 'Vermillion Sparrow' (which moves as Chu Lion?). The Free King also promotes, (to Golden Bird, and I am not sure how that moves). The King promotes to an 'Emperor' (?), which is not like the Maka-Dai-Dai Emperor, though, but a KD.

The CVP have received an email with a link to a "modern large shogi variant that seems to adapt chu shogi in ways that your readers may find appealing".  The page is in Japanese:

http://seesaawiki.jp/nari_shogi/d/%BC%EB%BF%FD

I declared the HaChu engine to be open source, so that it can be supplied by Debian for Linux. This begged for a Linux interface that could handle Chu Shogi, and unfortunately the 'mnemonic piece set' shown in the previous (Chu Shogi) comment is only implemented in WinBoard.

For XBoard I therefore used a representation with pictograms, (which a poll showed to be highly preferred by Chess players, despite their inferior neature), using as many of the 22 piece symbols that were already supported by XBoard. (But this was barely enough for the pieces in the initial setup. So I had to make some extra symbols for the promoted pieces, which are mainly slightly modified versions of the unpromoted piece that moves the same.

This is what I finally settled on:

Laziness prevailed in the cases of Blind Tiger (using the masked Horse that normally represents Nightrider), Reverse Chariot (using the Canon) and Go Between (using the Cobra); for the rest I am reasonably happy with how the unpromoted pieces look. The only new symbols used in the initial setup are the Lion, Ferocious Leopard and the standing and lying sword. The latter three were used in stead of XBoard's existing Falcon, Unicorn and narrow crown of the Grasshopper symbols, because the latter seemed more apt for designating some promoted pieces with unique gait. And swords seemed a very useful representation for the Vertical and Side Mover, as the way they point reminds you of the move pattern. (A similar argument led to the existing crosssed-swords symbol (the 'SMIRF' Archbishop) to represent the Phoenix, and the more roundish U.S. Marhall star to represent the Kylin.)

In the above picture the pictograms can be characterized as follows:

S . . S . S . . .
S . e e C C . C L
S . e e C C S S .
. . e e S S . . c

That leaves 14 new pieces that would have to be memorized (the Elephant counted double). If you already have used XBoard for Shogi, that is.

I wrote an engine (called HaChu) that can play Chu Shogi under WinBoard (the Alien Edition, as it needs multi-move support for the Lion). The idea is that in the future it would also be able to play the even larger Shogi variants Tenjiku, Dai Dai, Maka Dai Dai and Tai. But currently it plays only Sho, Chu and Dai Shogi (and Shatranj and Makruk, which are very Shogi like). I packaged engine and GUI together in a special Chu Shogi release. It can be downloaded from

http://hgm.nubati.net/WinBoard-Chu.zip .

WinBoard uses mnemonic piece pictograms in board sizes 'tiny' and 'petite', and traditional kanji in other board sizes. (Your OS must have Asian language support for that to display correctly.)

The engine is pretty strong (but you can always handicap it by hefty time odds). I played it on the 81Dojo server, and is able to compete with the strongest Chu players there.

Another variant which may be better than Heisei.

http://pika.cs.nctu.edu.tw/lit/MillenniumShogi.rar

One modern variant of Chu Shogi, called Millennium Chu Shogi(¤d¦~¬ö¤¤±N´Ñ), is played on a more open board. 40% of the pieces are set aside at setup and held in reserve. Once during the game a player may drop one of these on any empty square as long as at least one friendly piece now stays in the enemy camp(promotion zone, the farthest four ranks of the board); otherwise only drop on his own camp(the closest four ranks of the board).  If dropped into the promotion zone, the piece must dropped as its promoted piece.

The set-aside pieces are the Lances, Coppers, Silvers, Side Movers, Vertical Movers, Reverse Chariots, Kyrin, and Phoenix. 

Captured pieces do not come back into play, and the rest of the game is played as in regular Chu.

My friends and I ever played one Chu Shogi variant called 'Heisei Chu Shogi'.

http://pika.cs.nctu.edu.tw/lit/HeiseiChuShogi.rar

The description is as fallowing:

Heisei Chu Shogi, a variant of Chu Shogi, lets 8 kinds of relatively
weaker pieces get more opportunities to cooperate with power pieces
like Lion and Free-King. The rule is a transitional blend between
Chu Shogi and Modern Shogi.

All Copper General, Kylin, Lance, Side Mover, Silver General,
Phoenix, Reverse Chariot, and Vertical Mover are removed from the
borad and put aside in advance. Other pieces are still on the
original board setup of Chu Shogi.

Once during the game, a player may put his one of the removed pieces on an unoccupied square adjacent to any friendly piece as long as dropped piece can move. If dropped into the promotion zone, the piece may dropped as its promoted piece or promote on any subsequent move in the promotion zone.

For exemple, a Lance cannnot be dropped into the last rank; however, its promoted piece, White Horse, can be.

When captured, unlike Modern Shogi, the piece can't be dropped again. Other rules are as in Chu Shogi.






Another modern Dai Shogi variant is called Heisei Dai Shogi. It is like Heisei Chu Shogi owning Hand pieces, and has some special rules about captured pieces.

http://pika.cs.nctu.edu.tw/lit/HeiseiDaiShogi.rar

The rules are as following:

16 pieces are set aside at setup and held in reserve, and once during the game a player may drop one of these on an empty square adjacent to a friendly piece. 

The set-aside pieces are the Lances, Knights, Coppers, Silvers, Side Movers, Vertical Movers, Reverse Chariots, Kyrin, and Phoenix. 

If dropped into the promotion zone, the piece may dropped as its promoted piece or promote on any subsequent move in the promotion zone. As with dropped pieces in standard shogi, the piece may not be dropped on a square from where it cannot move. 

For exemple, a Knight cannnot be dropped into the last two rank; however, its promoted piece, Gold General, can be. Captured pieces do not come back into play.

There are special rules about some pieces regarded as 'prize pieces.' 

Except for King, Prince, Horned Falcon, and Soaring Eagle, other pieces capturing one of 'prize pieces' may become into Lion immediately or waite another occassion of capturing prize pieces. 

The prize pieces are Angry Boars, Cat Swords, Evil Wolfs, Flying Dragons,  Violent Ox, Iron, and Stone.

The rest of the game is played as in regular Dai.