33

Yes. The way I've done this in the past is to play a series of games with clocks starting with 10 minutes each on the clocks and then the rule for subsequent games that the winner of the previous game gets one minute less and the loser one minute more. This quickly stabilizes at a level where both players have good chances of winning.


28

Here is an example: [fen "8/4P3/8/4p1p1/2p3Pp/p4p1K/k1p2P1P/8 w - - 0 1"] 1. e8 leads to stalemate next move, while all legal promotions lose to 1... c1=Q followed by 2... Qf1#.


25

The board and pieces Quantum chess is played on a regular 8x8 chess board with standard pieces. Pieces have rings around them, filled in with colour. These rings show the probability that the piece is in that square. Modifications to existing chess rules A player is not required to move their king out of check and the game concludes when there is a 100% ...


25

OK The check must come from the knight (D'uh!) The black king must be on c5 for the mate The white king must be used to cover any empty squares to the right of the black king - thus the white king must move, thus there must be at least one non-checking move On a non-checking move Black can try to release the prison by Ra4 The only way white can cover this ...


23

Imagine a variation of chess without the rules about check and checkmate, where a player wins simply when he captures his opponent's king. In this variation, Kxd5 loses the game to exd5. Turns out, that's more or less how real chess works. The objective is to capture the opponent's king. If your king is under attack, you must deal with that threat. If there'...


23

In fact K+R+R can force checkmate against K on an open board. First move both Rooks away from the King and to different rows and columns. Then check the King with one Rook, say on a row. Whichever side the King goes, move the other Rook to limit it to a single row. Now the Rooks, moving only horizontally, can limit the defending King to just four squares on ...


22

The Matt Bengtson problem Prof. Elkies mentions is: [Title "Matt Bengtson, Chess Braintwisters (Burt Hochberg), no. 103. White to move & draw."] [FEN "4kn2/3p1pPp/4pPpK/6P1/8/2p5/1b6/8 w - - 0 1"] However, the problem is actually cooked with a win for Black starting with “3... f6!”, and there is no stalemate for White. The solution and the cooking line ...


22

In German, we would call this "Schlagschach". The German Wikipedia translates this to "Capturechess". However, I could not find an English resource that describes this variant. But there is a thread on chess.com where someone asked about the exact same thing. Edit: Thanks to @bitchaser who dug that thread more thoroughly and found a link to another page ...


21

There is no mention of excluding the regular starting position in Appendix F. of the FIDE Laws of Chess, so it's really Chess960 and not Chess959. I can imagine that there are chess programs or websites which do exclude the regular starting position, but this is against the official rules.


18

If these are two real kings, it is not possible. This is because one requirement of checkmate is that the black king is in check which cannot be achieved with any of the white kings, since it would put the white king in check. If you say that white has only one king and a nonstandard chess piece that moves exactly like a king (i.e. this piece can be put ...


18

Those are just the rules of the game. You could absolutely try to make the case that moving into check in such a situation should be legal, but playing by those rules wouldn't be chess anymore (it would be some variant). You could also ask why stalemate is a draw and not a win, even though the latter result would make more sense in a real battle. These are ...


17

A King and a Man (or commoner; i.e., a non-royal King) can mate a lone King. The longest distance to mate on a standard 8x8 board is 18 moves. The result quoted above was obtained by H.G. Muller in 2008, see this coment on chessvariants.com: http://www.chessvariants.com/index/listcomments.php?id=28770


17

I will answer from a different perspective: why Racing Kings (RK) has a rule to allow black a chance to draw, and why the same logic doesn't apply to chess. What is Racing Kings (RK)? Background for those unfamiliar with RK: Both sides start with all pieces (no pawns), arranged on the first 2 ranks of the chessboard, white on the right, black on the left. ...


17

Excellent question. The rules state that this is not possible. Castling can only be done once. This is explicitly mentioned under Guidelines II. Chess960 Rules: II.3.1 Chess960 allows each player to castle once per game, a move by potentially both the king and rook in a single move. [...] Specifically, castling (even if the king doesn't move) should still ...


16

Andrew Bartmess was the first Star Trek fan to reverse-engineer the game of tridimensional chess from the TV series (which never explained the rules). He sells his version of the rules for $9.95: Tri-D Chess Rules. In the most popular version of Tri-D chess (which Andrew calls the “The Federation Standard 5.0” rules), the game is played on seven boards, ...


16

It was discovered that e3 is a win for White: http://magma.maths.usyd.edu.au/~watkins/LOSING_CHESS/ICGA2016.pdf


16

And the correct answer, as always, is: "it depends on the position" :-) OK, assume that you start with Bb1/Nc1. Lichess says +0.1. But this is the sum of... the N generally standing a bit ugly on c1/f1, from my positional feeling the B doing some concrete attacking (Stockfish unsubtly starts with c3) other random concrete aspects the question you ...


14

I have found the trickiest part about playing 960 is the opening. So many possibilities! But, since the major pieces are random for every game it is unlikely you'll come across the same setup frequently enough to recognize some opening. So I say ditch trying to create one and stick with tried and true chess opening principles: Control the center, try not to ...


14

I cannot really speak from my own experience, but there seems to be some very decent sites about Antichess. Here is what this one has to say about the opening: "Just like in chess, the main goal in the Losing Chess opening is development of the pieces. One has to be careful, as the starting position is quite volatile, and some first moves even lose ...


14

Here are some mates I found: Queen and rook (limit the black king until the white arrives to help) [Title "KQR vs k mate"] [FEN "1R6/5k2/8/8/8/8/6Q1/K7 w - - 0 1"] 1. Qg8+ Ke7 2. Rd8 Kf6 3. Re8 Kf5 4. Kb2 Kf4 5. Qg2 Kf5 6. Kc3 Kf6 7. Kd4 Kf7 8. Qg8+ Kf6 9. Ke3 Kf5 10. Kf3 Kf6 11. Re6+ Kf5 12. Qg6# Queen and pawn (not sure if the ...


13

This post is in response to RemcoGerlich's request for a source for Annunuki's claim that the rule discussed here is an old rule. From A History of Chess by H. J. R. Murray, chapter 5, "Chess in the Malay Lands", page 103: "This leads to a still greater anomaly, a piece which is covering a check is deemed to have no power of giving check to the opposing ...


13

https://github.com/ddugovic/Stockfish Very active development, this is the Stockfish version used by lichess. What you need to do is search this macro: #ifdef THREECHECK Evaluation function: https://github.com/ddugovic/Stockfish/blob/master/src/evaluate.cpp Checks are given extra bonus unlike normal chess: if (pos.is_three_check()) ...


13

An infinite number of knights would be insufficient to force checkmate, assuming the enemy king starts some distance away and not surrounded. The knights are too slow and not enough of them can chase an enemy king that simply runs away. A rook and two bishops, on the other hand, could force checkmate. It's rather easy to force a position like this: [FEN &...


12

Douglas Crockford has written an accurate overview of Chinese Chess (or Xiangqi) from the perspective of a chess player. I quote the following: The Board Xiangqi can be played on a 9 by 10 uncheckered board. The board is separated into two territories by a river running horizontally through the center of the board. Bishops are unable to cross the ...


12

In my answer to the same question over on math.stackexchange, I discussed general m by n boards. Here I will just give a winning strategy for Player 2 on the ordinary 8 by 8 chessboard. It's based on the following pairing of squares: a1c2, b1d2, c1a2, d1b2, e1g2, f1h2, g1e2, h1f2, a3c4, b3d4, c3a4, d3b4, e3g4, f3h4, g3e4, h3f4, a5c6, b5d6, c5a6, d5b6, e5g6, ...


12

Your "checkless" chess AI would run into problems with the stalemate rule. It would consider the poaition with white king on a6, white pawn a7, black king a8, a win for White because wherever Black moves his king it will get captured. In standard chess, of course, the position is a draw.


12

There is likely not a way to force a loss. Selfmates are relatively rare, and one can probably not be forced from the opening position. The best plan, paradoxically, is likely to try to capture as many of the opponent's pieces (but not pawns) as possible, while keeping your own pieces to be better able to force your opponent. The opponent's pawns are kept ...


12

There is a similar ancient question, but this isn't a duplicate since White may move anywhere. For an upper bound, I can prove a guaranteed win for White in 5 moves. Indeed, it is reminiscent of Scholar's Mate. [FEN ""] 1. e3 null 2. Bc4 null 3. Qf3 null 4. Nh3 null 5. Ng5 With Black to move, as White has now used up their five given moves, ...


12

Are you familiar with the variant known as Crazyhouse? Basically, if you capture an opponent's piece, you can spend a later turn to place it anywhere you like on the board, as your own piece. This creates a situation where same-coloured bishops are possible, should you so choose. The ability to create bishop 'batteries' can be quite good, presuming that you ...


11

Castling is the only legal chess move in which two pieces are moved. You can verify this by searching for "FIDE Laws of Chess" and reading "Article 3: The moves of the pieces" (I do not provide the URL here because unfortunately it frequently changes).


Only top voted, non community-wiki answers of a minimum length are eligible