All this talk about relative values is great. I would never have guessed that I would be interested in it, but here I am reading every word: and LOVING IT!! Even the decimal point values don't get me worn out, because I can see that there are logical reasons for using them. It rather comes to mind that the tendency for sticking with single-digit values in chess has always seemed a bit fudged. Maybe with the broader perspective of a more complex game, rethinking the chess piece values for 8x8 games won't be such an impossible task. At least we may find new reasons to corroborate the same values that the past greats agreed on. In any event, this new perspective cannot do other than expand our appreciation for chess as it has been all along. And what about when the appreciation level starts to impress the general public? What are people going to be saying in Peoria, IL, come October 2003?

I can't help but wonder what is going to happen when chessplayers start to catch on to the idea that gothic chess is a new frontier that they, with their race horse mentality in chess already, are well poised to enter; that it makes for a playing experience that is every bit as enthralling as chess, but in the process, you get whiter knuckles? (The larger playing board will make a better sized table for coffee and doghnuts, and besides, with the new plasma TV monitors coming out, a wider board will fit more beautifully on the screen...)

I don't know much about tournaments, because I've never played one (my current entrance in the BigBadWolf's 5-day is my first of any kind!) but it seems to me that there may be a lurking popularity explosion in the near future with this game. I am so glad for Ed Trice that he has secured a patent. I get the feeling he is going to be stretching that puppy to its limits. Therefore, I wonder what preparations would be prudent for the advent of tens of thousands of people all wanting gothic board sets all at once? It takes a few months to get production up, and it takes a good bit of diligence to enforce the protection of patent violations. When stuff is made in -well, let's face it- China, the black market for patented items is bigger than the legitimate market. If overseas sales of gothic board knockoffs proliferates, it will be pretty hard to enforce any kind of control over importation of cheater sets into the swap meets and flea markets. How can you bust a guy pushing a 3-wheeled cart in Chinatown?

Another field in which I have no experience is marketing, but I do know that it can get expensive to have a marketing firm do a contract for your new product. I've heard of guys going broke just trying to keep up with preliminary expenses. It seems to me that using the internet here, Ed could ask people to take a sample board and (four extra?) pieces into local coffee bars where chess groups meet (I've heard of one in Glendale, CA, where Armenians get quite serious about their national pastime, chess) and set up a board to have a little fun. We could answer questions, suggest visits to this website, and report back to Ed without running up any marketing expenses for him! I would not be surprised one iota if within a week, men start walking in with homemade boards and handcarved pieces! Just be sure you have a place to duck when the arguments erupt!!

But presuming all these details get worked out, has anyone considered what to do if this gets popular by summer or even the big rush next Christmas? /Fx/

The "Dual Steed Smother" is one of my favorite Gothic Miniatures. In it, you place your Chancellor in the f-file, make one strange knight move after having baited your opponent to activate his Bishop to chase your Chancellor, and on the very move you are so threatened, you mate with the Knight.

If you go to archived game 57339 you will see this in action.

http://www.BrainKing.com/game/ArchivedGame?g=57339

is the link. It should be noted that you can execute this in 4 moves, but I had to "challenge" the potential placement of his bishop on the long diagonal, or else the miniature cannot be accomplisged.

Hi Felix, you must have been online the same time as me, and editing your previous post, since I saw 3 or 4 versions of it. I am a speedreader, and I could swear the text changed immediately after I read it...then read it again, then it changed again! I started rubbing me eyes and blinking!

Anyway, I am in the process of doing "Dog and Pony Shows" to attempt to procure capital to fund the next stage of the venture. I do have boards and pieces already made, I think I mentioned that. A picture of one is now on the webpage at:

http://www.geocities.com/bow_of_odysseus/standard.html

The pieces are high quality, the boards are machine washable and never wrinkle (made out of something akin to mouse pad material.) The patent is becoming international, extending the umbrella from Europe to Hong Kong. I am not so much concerned about wheel barrow sales as I am about software distribution. If somebody creates a Gothic Chess program, I will have no choice but to go for the throat.

I intend to use the patent for licensing agreements. Parker Bros. or Hasbro or Ideal Toys want to make sets, fine with me, pay an annual flat fee plus a small % of the sales, provided I get to write the accompanying documentation.

Anyway, more on this later, I have to finish my 159th version of the Business Plan :) Why can't the banks just give me the 2.2 million dollars and trust me??

Just reviewed this game and it does rely heavily on your opponent not moving the e, f or g pawns. How often have you come across this type of opening? I would have thought most players would move at least one of these pawns to activate the diagonals? Is there a corollary which builds on this opening in these instances?

I have seen this happen a few times. The first I published and annotated in the July 2000 issue of Gothic Chess Review. There is no corollary associated with play other than the knockout punch.

Here is the other game:



David Vales vs. Biju Samuel

1. i3 d5

Dave often plays i3 at the start of the game to invite the Pawn push that reveals the Bishop’s attack on the Rook. It is a short-lived attack.

2. Nh3 h6

The geometry of Knight-Pawn spatial relationships indicates that any singular push of a Pawn one rank from the starting position will functionally disable an enemy Knight’s ability to advance two ranks closer on the next move. White’s Knight on h3 is so stymied by Black’s h-Pawn.

3. Bi2 i5

This is a favorite Pawn push of Biju’s, aimed at dislodging the Knight on the h3 square. With the exposure to the King created by ...h6, White crafts a plan to use the tempi lost by Black in dispelling the Knight to move it closer to the King, then “hope”....

4. d3 i4
5. Nf4 c6?

Black is missing the point. The dislodging of the Knight was not a positive realization, and it is most dangerous.

6. Cf3!

A very, very sneaky move! White has set up the deadly revealed check.

6 ----- Nj6??
7. Ng6#

Interesting. So, the Archbishop is the only piece whose value you feel needs tweaking from its computed "safe check" value. I'd like to challenge that position, in the hope that the ensuing discussion will lead to greater understanding. First, two Bishops often work well together and I am not sure that it is obvious that an Archbishop should be worth more than a Bishop pair. I would be willing to grant that an Archbishop should be worth more than a Knight and Bishop for the same reasons that a Queen should be worth more than a Rook and Bishop, one of which would be that an Archbishop and Queen can "change the color of the Bishop." When discussing this, we should not forget that the actual value of a particular piece is dynamic and depends strongly on the position. Since the Archbishop is a jumping piece, one finds that it often joins the battle earlier than the Rooks and Bishops, so in the initial phases of the game, the Archbishop should be considered more valuable than a Rook or Bishop pair. In the endgame, however, the jumping capability is less important and it would not be surprising to find that a Bishop pair or even a Rook could be equal to an Archbishop. Of course, I still would not exchange an Archbishop for a Rook in the opening or middlegame, since my opponent's Arcbishop might checkmate me before I made it to the endgame :-). The issue of "dynamic value" also applies to the situation of a Rook versus two minor pieces. Certainly very few good chessplayers would play Bxf7+ Rxf7 Nxf7 Kxf7 as White for the reasons given. However, notice that this assumes that the exchange took place in the early to middle phase of the game, before the Rooks would be free to roam on open files and ranks; a Rook is very nearly the equal of two minor pieces in the endgame (and a Rook and Pawn is considered fully equal to two minor pieces in the endgame). I believe the reason a Rook is downgraded from 6 to 5 in 8x8 chess has more to do with the fact that two minor pieces can attack a square twice (unless, of course, the two minor pieces are a Bishop pair :-) ) rather than the actual strength of the Rook compared to two minor pieces, and that this is why a Rook is considered to be worth less than two minor pieces. In fact, one could argue that the Rook is the only 8x8 piece whose value was tweaked from the "safe check" value, since the "safe check" value of the other pieces are essentially the accepted values.

And another aside that I have heard is that a bishop pair is worth more than the sum total of the two bishops individually, that is, taking the first bishop is worth more than taking the second. Any thoughts on this?

Yes, that is usually true. If the position is "open" so that the Bishops have the run of the board, it is certainly true that the Bishop pair is worth more than the two individual Bishops. However, there are some positions (usually "closed", with blocked Pawn chains) which favor two Knights. In fact, the synergistic effect of the Bishop pair is one of the reasons I would question valuing an Archbishop more than two Bishops. (Of course, if you take this into account, you might still augment the value of the Archbishop... :-) )

One way to think about the piece values subjectively is to imagine what you are discussing in an ending against a lone enemy king. While it is true the Archbishop is stronger than a Rook, would you like to try and win Rook vs. King or Archbishop vs. King?

:)

I posted a mate in 8 for Archbishop vs. King at:

http://www.geocities.com/bow_of_odysseus/deadly_arch.html

It is a real brain teaser of a problem to mate with the Archbishop on an empty board!

One way we can compare something like a Bishop Pair to an Archbishop is to try and find "Longest Wins" in the endgame. I know in chess, the Longest win from a Bishop Pair is about 67 moves. That was on an 8x8 board.

But in Gothic Chess, examine the ending of King vs. Knight + Bishop. It is almost a draw! Whereas in chess the N+B will mate in either of two squares, those of the same color as the Bishop, in Gothic, you can only force mate on one of the squares! The square of the same color as the Bishop that is closest to the enemy king vertically (not horizontally across the files) is the only one the mate can be forced in.

So, we need to look deeper at the discussion of piece values in the endgame, because in Gothic, even things like the Lucena Rook and Pawn vs. Rook ending need complete rewriting.

According to Reuben Fine in "Basic Chess Endings," the "longest mates" (on an 8x8 board) are as follows:

Pieces.................Longest Mate
----------.................--------------------
K+Q vs K.................10 moves
K+R vs K.................17 moves
K+B+B vs K.............18 moves
K+B+N vs K.............34 moves

All but the K+B+N vs K should be essentially the same on a 10x8 board, where any extra number of required moves would be small and due only to the extra space on a 10x8 board. The K+B+N vs K on a 10x8 board is more interesting, as Ed has pointed out. Once the lone King has been forced to a corner opposite in color from the Bishop, the lone King must be forced to the closer corner of the same color as the Bishop, otherwise the corralling procedure will fail. I haven't studied this enough to know for sure if it can be forced at all (although I suspect Ed has worked it out). The K+C vs K is easy since a Chancellor can be used as a "supercharged Rook." The K+A vs K is not really hard, but the procedure certainly has no counterpart in regular 8x8 chess, so seems strange when an 8x8 chessplayer first tries it.

I'm not sure I understand why Ed thinks the Lucena position needs a complete rewriting on a 10x8 board. The winning procedure is independent of the "width" of the board and would be the same on a 20x8 board. I suspect that many, if not most, endings do not really depend a great deal on the "width" of the board (the K+B+N vs K ending being a notable exception); the "height" of the board is the determining factor. I freely admit that I don't have a proof of this assertion, but it would surprise me if 8x8 endgame theory changed significantly on a 10x8 board. For those who are interested, a more dramatic geometric effect is produced by using an Omega Chess board (10x10 with 4 corner squares). On this board, several strange things happen:
1. K+R can no longer force mate on a lone K.
2. K+B+N can no longer force mate on a lone K.
3. An _unassisted_ Queen can force mate on a lone King.
4. K+N+N _can_ force mate on a lone K.
Omega Chess turns out to be a much slower game than Gothic Chess, and I'll leave it at that, since this is a Gothic Chess discussion board (and Gothic Chess is more exciting anyway).

in group 2

gothicchesspro has scored another victory and stands first with the 100% score of 3/3. Schaakhamster is second with 2/3. The other big fish in group 2 appears to be pawnchucker (question to gothicchessspro: do you know who he is??). Although he hasn't finished any games yet he holds a huge advantage in 2 games and also has an advantage against Schaakhamster. He appears to stand equal against gothicchesspro (at first glance)

In group 1

Juangrande drew first blood by defeating tonyh from England.

Basically this ending (pronounced Lou-Chen-Ah) is a staircase procedure. As you mentioned, you would think the height or vertical distance from Rook to King would be the governing factor. But Lucena themes are numerous, and in one of them there is a sneaky "end around run" which the width of the board allows.

It is a draw on an 8x8 board. Move it to a 10x8 board, it is a win.

First, a typical Lucena win. White king on e8, white pawn on e7, white Rook on f1, black King on g7, black Rook on d2. This is on an 8x8 board.

Lucena published a manual in 1497 (a mere 5 years after America was ‘discovered’ by Christoval Colon, a.k.a. Christopher Columbus) wherein certain endgame techniques were mentioned, but, curiously, the critical position was not in that tome! In truth this endgame is an age-old one, but an Italian author named Salvio was the first to document the winning technique for White in the year 1634, and even he attributed the composition to a previous mentor named Scipione Genovino. That historical tidbit aside, White can win independent of the side to move by using the “staircase” technique.

1. Rg1+ Kh7 2. Rg4! (placing the Rook far enough away from the enemy King to avoid a trivial banishment while allowing for the quickest check-intervention block as the King marches towards the Rook. Playing 2. Kf7 at once achieves no gain since the Black Rook delivers a long sequence of harassing checks.) 2...Rd1 3. Kf7 Rf1+ 4. Ke6 Re1+ 5. Kf6 Rf1+ 6. Ke5 Re1+ 7. Re4 and the win is trivial now.

Let's look at another theme.

White king on h6, white pawn on g6, white Rook on a7, black Rook on b8, black King on g8.

This position represents another common 8x8 endgame where White’s g-pawn is functionally useless. It appears Black’s Rook is serving a purely passive role, but a draw is all White can hope for with 1. Rg7+ Kh8! 2. Rh7+ and now Kg8 draws. Black needs to avoid only 1...Kf8?? which loses to 2. Kh7!! Rb1 3. Rf7+ Ke8 and now the pawn promotes.
Transplanting the drawn position onto the Gothic chess board results in a win.

Black loses the Rook at once after 1. Ri7!! since mate is threatened immediately with Ri8# if the Rook moves. After 1...Kh8 2. g7+ Kg8 3. Ri8+ Kf7 4. Rxb8 Black is toast. Black likewise does not have the resource 1...Kf8 2. Ri8+ Ke7 3. Rxb8 which loses even quicker.

I hope this analysis is accurate, I am doing this without sight of a board.

I updated:

http://www.geocities.com/bow_of_odysseus/deadly_arch.html

to showcase an old speed game I found where my Archbishop checkmates on e7, all by itself. It is a cool game. Let me know what you think :)

Yes, your analysis is accurate. I'm also impressed with the historical background. However, I don't believe this example illustrates the difference between an 8x8 and a 10x8 board for Rook endgames (if, in fact, there is any difference). A Lucena position, according to my sources, is a position where the White King is on the last rank, directly in front of his Pawn, and the Black King is off to one side of the Pawn. As you pointed out, the standard winning procedure is to "build a bridge" as in the line you gave. This is the same on either type of board, as long as the Pawn is not on a Rook file. The other position (White: Kh6, Ra7, Pg6; Black: Kg8, Rb8) is called a "passive defense" rather than a Lucena position and is a draw if White's Pawn is on a Rook or Knight file, and a win for White if the Pawn is on a Bishop or central file, with the winning procedure exactly as your "Gothic" line. However, "passive defense" is still a draw on a 10x8 board if White's Pawn is on a Knight or Rook file (a, b, i, or j) and this is no different than on an 8x8 board. My point is that it appears (to me, at least :-) ) that the Rook endgame theory of the 8x8 board carries over "mutatis mutandi" to the 10x8 board. In fact, I can't think of any other endings that depend on the geometry of the board (10x8 vs 8x8) the way a K+B+N vs K ending does.

An interesting question in this topic is whether either a K+A+P vs K+R or K+R+P vs K+A is a win (or, under what conditions either one would be a win).

Ah ha, now I see our difference honed in upon, finally! OK, remember the original 10x8 board was 'Capablanca' which had Bishops on the d and g files, not c and h files. For this reason, I 'translated' the concept of the file name to the literals (a,b,c,d,etc) from the descriptive notation tying a piece to the back rank (rook pawn, knight's pawn, etc) since the descriptive notation would vary depending on which 10x8 board you used!

So, placing the pawns in the rook file on the 8x8 board was just transplanted to the h-file in Gothic.

I was caught in a catch-22: using descriptive notation would be different depending on your 10x8 style of preference, yet using hard coded literals should not be done by rote.

I did not re-translate the destination files when moving it onto Gothic.

But everything else was true :)

The draw I showed in 8x8 chess would be a win on the 10x8 board, moving the EXACT position as was shown.

Of course everything you said was true, Ed; I would expect that from you. :-) My point was simply that the endgame theory of regular 8x8 chess carries over essentially unaltered to the 10x8 Gothic Chess board (with K+B+N vs K a notable exception). In the particular example we were discussing, White wins against "passive defense" if there are at least two squares on the "short side" of the Pawn, and this is true on both the 8x8 and 10x8 board.

Have you ever looked at the question of K+R+P vs K+A or K+A+P vs K+R? That appears to be an interesting question and a true test of the relative strangth of the Archbishop and Rook.

I have a web page at:

http://www.geocities.com/bow_of_odysseus/internat_open_01.html

I would like to know if I interfaced correctly with the web pages here, and if you can see your games using my page as a source.

Thanks in advance for any feedback.

Juan, the endings you mentioned would have to be some of the most treacherous possible! I could always write a program to solve the endings and report the results back so I would know how long the win would take from any position. I could then make this database avaialbe for everyone.

The problem is: the construction time is long and I would need to use about 4 computers to solve these endings.

My partner and I already generated large databases for the game of checkers. We have every solution for any endgame involving 8 pieces. That is roughly 111 billion positions!

We also have "distance to win" information for the 19 billion seven piece endings. This takes up 7 gigabytes on your hard drive in its compressed form!

So, just to let you know, I know how to solve endgames via retrograde analysis. Before we do something like A+P vs. R, we need to solve all of the endings such as:

A vs. R
AQ vs. R
AC vs. R
AA vs. R
AB vs. R
AN vs. R

Why? Because a pawn could promote to ANY one of those pieces, and we need to know the result of ALL of the conversion information before we can solve the pawn ending!

For this reason, it becomes a big task, but I am up for the challenge.

http://www.geocities.com/bow_of_odysseus/vortex.html

I started building the page discussing this strategy, a very important aspect of Gothic Chess.

The task of bringing checkmate upon a lone King with only a Knight and Bishop has always been a good exercise to learn coordination of the minor pieces. Capablanca highly recommends it in his Chess Fundamentals, bemoaning the fact that many otherwise excellent players cannot corral his King in the required 50 moves (no pawns to move). This ending translates somewhat to the 10x8 board, however, it seems to me that the time it takes to achieve the mate is longer than on an 8x8 board, assuming good play by the lone King, although 50 moves seems to be sufficient. It is more challenging to force him into the wrong-color-corner (the standard preliminary position) while eliminating his recourse to the long side, but it is possible to do as far as I can see. I would like to see this question explored empirically, for the fact of what works is the final test in this game. If the enemy king can slip out to the 10-square side, he is then able to somewhat double the number of moves required to mate. If he does escape once to the 10-square side, it looks like he can be somewhat contained at the opposite, wrong-colored-corner, inasmuch as prevented from doing the same thing again, for if he could repeatedly escape, the knight and bishop would be then incapable of winning, regardless of the number of moves. This second containment appears to have something to do with the coordination of the offensive pieces, and especially the pattern of the knight moves. A student of this ending will quickly discover that while the knight has some usefulness while located on a square opposite in color to the bishop's squares, the highest power is always obtained when the knight and bishop are on the same color squares. There are several consequences to this doctrine.

If there is anyone else as interested in this exercise as I am, I would suggest that perhaps a tournament could be set up using only these 4 pieces on a 10x8 board. A win for Black (or White?) would consist of escaping checkmate for 50 moves, while a win for White (or Black) would be achieving checkmate. We could call it the "Capablanca Memorial Endgame Tournament," because he pronounced the value of its rigorous study to improve chess at large, and he was given to dabble in 10x8 format. I would be interested to see how other players handle this ending.

It is my sincere hope that the question of whether or not the 50-move limit is sufficient to secure checkmate does not pose a problem for keeping control of the patent on gothic chess. We could find out that it takes a more skilled player to win in this larger format, but that does not necessarilly mean that the rules of the game need to be changed, for new rules would mean a new game, and a new game would not be covered by the current patent.

There is much to be gained by toying with this ending, and I would like to share my own fascination with gothic chess fans, if they are interested. /FX/

The answer to all of your questions appeared in the April 2001 edition of Gothic Chess Review. The ending can be a forced win without expiring the 50 moves. Some of them just barely squeak by. Maybe I will compute this database. It will give me something to do.

:-) It would certainly be interesting to see the results of such a database! The K+A+P vs K+R and K+R+P vs K+R certainly would be a very interesting test of the Archbishop versus Rook. I hadn't really intended for you to go to _that_ much work, though! I will go out on a limb and re-state my hypothesis that the Archbishop and Rook would be approximately equal in an endgame. So, if you do create such a database, I want to be one of the first to be told of the results! :-) :-)

By the way, thank you so very much for taking the time to contribute your pioneering knowledge of Gothic Chess. I, for one, appreciate it very much!

That sounds like a very interesting exercise and I would certainly be interested in playing a two-game match of it. Would you like to ask Fencer if he can set it up?

I can start working on the code for the BN vs K database tonight. It will not be slick, nor fast to execute, but I can get it up and running in no time. I think the longest win is about 38 moves (for one side) so it will need to loop around 75 times (38 times for the winning side, 37 for the losing side) and I am not sure how long each iteration will take to complete.

If I generalize the code to solve any db configuration, I would need to spend at least a week making it very fast.

OK, now for a contest:

Try to set up the most difficult position for a knight and bishop to mate a lone king.

So, tell me the location of:

White King
White Bishop
White Knight
Black King

For the longest white to move and win position you think there is. The winner I will give a free stainless steel Gothic Chess commuter mug, complete with thermal lid.

Post your submissions, one per customer, with the subject heading "B+N vs. K Contest"

OK?

There is a bulletin board in England where there are a few people who do not like me too much. But, the checkers program that my partner and I created, the strongest one in the world, has a reputation.

For those looking for a laugh, read the first line of the post:

http://checkersolutions.co.uk/cgi-bin/board/messages/7119.html

I was not the one who posted it, it was just brought to my attention :) P.S. My programmer partner is Gil.

Hi Ed,
you can use some HTML tags here, especially links, like this:
http://www.geocities.com/bow_of_odysseus/internat_open_01.html
It is more comfortable to click on a line instead of copy and paste it.

Here is a link for the year 2000 Championship. testing the link feature from within here...

Year 2000 Championship

Worked for me

Ed, what an amazing concept! In one move, you have gotten to the crux of this issue, that is: What are the starting positions? I was going to suggest that the 4 pieces be located in the 4 corners of the board, just to make the playing field even, and to get on with the action. But you have one-upped me on that level already! For if we were to play this out, we would have as many as 12 endings: 6 with the defensive king on a light square corner, and 6 on a dark. Some of these 12 games may work out to be insignificantly different. I will have to look at this some more, though, before I submit my contribution for your contest. I will be interested in the results!

Your offer of a thermal mug for the winner makes it all the more appealing, especially with that thermal lid thrown in. I've always wanted a thermal lid!

I would like to know, how can you be sure that a program can find all the best moves for the defensive king? Sometimes a hidden flaw leaves a program "blind" to a line of play. That's why I thought a tournament would put the theory to a practical test. /Fx/

My quick suggestion is that all the white pieces are in one corner, King right in the corner with the bishop one out or one up (opposite colour to corner), and the black King in the opposite diagonal corner. Before the King can be maniputlated you already have 8 moves for the King, 4 for the knight and possibly 3 for the bishop ... 15 moves before game on! Of course the actual placement of the black King is not so critical so long as he can get to the corner quickly without undue interference. :)

Hi Felix,

Just so you know, the longest win on the 8x8 board for B+N vs. sole K does not occur with the pieces on the perimeter in the 4 corners!

The longest 8x8 win is as follows:

White King = a8
Black King = c8
White Bishop = e8
White Knight = h2

Solution with Black to move and lose:

1... Kd8 2. Bf7 Ke7 3. Bc4 Kf6 4. Nf3 Kf5 5. Bd5 Kg4 6. Kb7 Kf5 7. Nd2 Kg4 8. Nc4 Kh3 9. Be4 Kg4 10. Kc6 Kh5 11. Nd6 Kh6 12. Ne8 Kg5 13. Kd5 Kf4 14. Nf6 Ke3 15. Nh5 Kf2 16. Kd4 Ke1 17. Bd3 Kd2 18. Nf4 Kc1 19. Kc3 Kd1 20. Bc2+ Ke1 21. Kd3 Kf2 22. Bd1 Kg3 23. Ng6 Kf2 24. Bh5 Kg1 25. Ke2 Kg2 26. Bg4 Kg3 27. Bf3 Kh3 28. Kf2 Kh2 29. Bd1 Kh1 30. Be2 Kh2 31. Bf1 Kh1 32. Ne5 Kh2 33. Ng4+ Kh1 34. Bg2#

Felixe mentioned:

"I would like to know, how can you be sure that a program can find all the best moves for the defensive king?"

The database starts by placing the pieces on every square and asking the simple question: Is the side to move in checkmate? Yes, identify this as a loss in 0. No? Is the side to move in stalemate? Yes? Identify this position as a draw. No? Can the side to move win one piece? Yes? identify this position as a draw. No? There is not enough informaiton to resolve the position yet, keep looping.

Eventually, it finishes "pass #1" and has identified all of the losses and draws. Then, by definition, every position on subsequent passes must be either play into: a pre-resolved win, a pre-resolved loss, a pre-resolved draw, or remain undetermined.

In order to resolve a win, only one move for the winning side need to lead to a win. In order to resolve a loss, EVERY move for the losing side must lead to a win for the other side.

As you loop around, doing pass after pass, you have a variable that indicated whether or not you resolved something on a particular pass. After so many loops, there may be nothing left to resolve. By definition, any of the UNKNOWN positions must be draws, so you mark them as draws then you are done.

Why you consult the database in a position, here is what you do:

1. Determine if you are in a win, loss, or draw to start. This is stored in the db.

2. Generate all legal moves from the position.

3. If in a win, look up the # of moves to lose for the other side to move. Pick the smallest number you find, and make the move leading to that position.

4. If in a loss, look up the # of moves to win for the other side to move. Pick the largest number you find, and make the move leading to that position.

5. If in a draw, make sure you do not move into a loss! (It is impossible to select a move leading to a win, or it would not be a draw.)

In this fashion, the program can always play the best defensive move for the weak side, and fastest winning move for the strong side.

By the way, my partner and I have already done this for the game of checkers. The longest win we have takes 253 plies to finish! We verified it is impossible for any program on the planet to play it properly! Our program, called World Championship Checkers, comes with an 11-CD installer, and these CDs are compressed! Now that's a lot of data!

Ed,

Here is my setup for the contest:

Black King = a8
White King = c6
White Bishop = c5
White Knight = b5

I only have a mate in 25 moves for White! I can not seem to get more!

I'll make an educated guess for the setup, since I don't have the resources to conduct a detailed search. :-)

White: Ka8, Be8, Nj2
Black: Kc8

Of course, the mirror image positions should be considered equivalent:

White: Ka1, Be1, Nj7
Black: Kc1

White: Kj1, Bf1, Na7
Black: Kh1

White: Kj8, Bf8, Na2
Black: Kh8

Hello everyone, Ed has asked me, as an old GCA member, to say a few words about Gothic Chess. I was a member of the old GCA (Gothic Chess Association) back a few years ago. Even though I never played any rated games, I do have some Gothic experience under my belt. Schaakhamster, while I appreciate the compliment, I would hardly consider myself to be a "Big Fish". Basically I know some of the what not to do's sprung from lessons of hard-knocks. Those lessons were handed to me by some of the other old GCA players who I used to battle with on a java applet site that was developed by the GCA. Sadly, the site was only in existence for a short period of time. These are the first Gothic games I've played since the GCA went into legal term-oil a few years back. It feels good to get back into it. I hope Ed can revive his old quarterly magazine "Gothic Chess Review". There was many a pearl to be plucked from those pages. Ed and a dozen or so other players whom seemed to be the core of the GCA contributed often and passionately. Unfortunately for me the GCA was in Philadelphia and I live in the Los Angeles area thus games were hard to find. Hopefully with Brian King, Gothic Chess will have a new home and a strong, solid future.

I would suggest that anyone who really wishes to learn this game ask Mr. Ed Trice ( GothicChessPro)if he has any surplus of his Gothic Chess Review magazines laying around. Those magazines are not only enjoyable to read, but will really give one a good fundamental understanding of the game.

Perhaps, if might be so bold, and, if Ed did have electronic copies originals, they might be posted on his web site?

I would like to thank Pawnchucker for the kind words. Had I known who Paul was when I first started playing, and that he had access to GCR, I certainly would have embarked on a different opening plan in our game :)

I am in the process of sifting through some of the old GCR issues and making the material available online. There are some other interesting items presented here as well. Here is what is up and running so far:

A discussion on the evolution of chess, including some interesting tidbits about the early days of Gothic Chess.

Why Change Chess?

An interesting attacking game, showing the hairline that separates over aggression and proper defense. Ending with an Archbishop sacrifice and a nice combination.

Game of The Month

One of the first strategic notions I uncovered early on was that a Chancellor + Bishop attack could take every piece off of the board. Here is a discourse on this lesson, ported directly from GCR.

The Chancellor's Vortex

A photo gallery from the year 2000 Championship, our largest over-the-board tournament ever. Hopefully many more events will be hosted in the future!

National Championship 2000

I will gradually bring more items online, especially if I start computing database results for endgames.

That's all for now.

--Ed

pawnchucker is a veteran; so I shouldn't take the asskicking he's giving me too harshly; my ego is saved =)

Thanks everybody for the great and valuable discussion here. I wish that other boards would be that good :-)

And thank _you_, Fencer, for implementing Gothic Chess on your site and providing us with such a nice interface for playing and discussing it!!

I will up the ante, if Fencer can accommodate. I will start to compute the B + N database on Saturday. When it is done, I will need a day to hook it up to some form of graphical user interface. I will probe the database for the most difficult position.

Any who wishes may enter the contest to try and win most swiftly against the database from the hardest position.

Whoever wins the quickest will receive a Gothic Chess set for the cost of the postage.

This is provided that

a) Fencer can provide some sort of temporary interface to set up positions for the purpose of this contest

b) the games remain private

c) those involved before other participate do not give away the position.

On a final note, I reserve the right to change the position if there are more than one arrangement taking the same length to win.

Is anyone interested? Send me an email to GothicChess@aol.com if you are, tell me your nickname on here, and I will post the official entrants online.

Fencer will verify that each name is unique, and that someone is not using more than one handle from the list.

--Ed

I'm not sure if I understand what you are up to. You want me to provide a set of started games with a specific positions and let people to win them?
It is possible with no changes to the current system [which is good because I am short of time for anything out of my schedule]. Just give me the required position with all moves from the start and I can create all corresponding games.

Suppose I said place a white Bishop on a2, a white knight on j5, a white king on a1, and a black king on j6. Could you do something like that?

Yes, I can. Actually, it requires one minor change but it is very easy to implement. And who will play all these games, the competitors against you?

I do not know what the exact position is as of yet, but when I do, yes, I will play the losing side of sole king, and everyone else will play the strong side with B+N. We may switch sides if they want a demonstration of the winning technique. I am still a ways from this. I just ran a test last night on the code to make sure everything is in place.

In the 37,957,920 positions in the database, only 9,489,480 are unique, the others are reflections and rotations. I ran the test over all of them just to make sure.

It found 532 checkmates and 17,576 stalemates. These results are both encouraging since they are a multiple of 4, and the board will produce 4 mirrors of every pawnless endgame in Gothic Chess.

I can reduce the size of the database by 400% when I get a more sophisticated lookup scheme, but for now, I just want to compute the data.

It took 15 seconds to do this first pass, which is the quickest pass. Each subsequent pass will take about 1 minute with database lookups and move generation. So, once everything is in place, it will only take about an hour to solve the database.

Then I have to write the code to look it up and translate the best move to a move on the board.

Okay, I've just added the support for position setup. When you give me the position, I will set it for all games you create for your competition.

I'm still looking at your 8x8 solution. I thought I found some weaknesses, but I looked again and I had presumed wrong.

Yes, I still think this is an excellent study, and that to the extent that he recommends it to anyone who wishes to improve their play, Jose Raul Capablanca was, and remains a good counsel.

I have found myself too busy to drop everything and generate my answer just yet. I am very much interested, though. I hope everybody with the time to spare on this doesn't leave me in the dust because I have other duties to which I must attend. Please consider keeping a record of these proceedings, so that I will be able to see later what I missed.

Income tax, property tax, end of the month, kids are sick, Girl Scout Cookie pay-up time, new songs for Lent, fix the lawnmower, some vandal broke the back window of my Volvo station wagon (he's lucky I didn't catch him), banking, paperwork, computer upgrades, family wants to go on a vacation, another house in escrow, water pump leaks on the Plymouth, plus general maintenance. Oh yes: work, too.

I'll be back! /Fx/

I guess for us pawns that we will only need one slot free for when the tournament begins. Is that right Fencer?