Chess324

[GONeill]

chess324 is a subset of DFRC, but has no positions clearly beyond the draw range, and doesn't require the special rules of castling. For some purposes there may be a need for more than the 648 game matches possible with chess324, so there may still be a reason to continue to explore DFRC, but for the vast majority of uses 648 games should be enough between two particular opponents.

So engines do not have to have FRC support to use these openings ? You start a standard chess tournament and the GUI and engines will understand ?

Yes, that's right! They are just alternate start positions, all standard rules of chess still apply. Of course they are not legal start positions (except one), since they cannot be created by a sequence of legal moves from the normal start position.

An interesting effect of this is that GUIs that don't support eBoard use in Chess960 work fine with my drivers in Chess324. I just played a game in LucasChess with my Chessnut board against one of the engines and there were no problems at all. Arena won't work for this with boards that don't have piece recognition since you won't be able to set up the starting position but otherwise it should be OK, I think, with any other combination of eBoard driver and GUI that I support:

https://goneill.co.nz/chess.php

Larry: I'm thinking of asking Lucas if he can add this as an option to the 'Initial Position' screen of his program but before that it might make sense to have a standard, common list of positions each with its own code so that, for example "rbbqknnr/pppppppp/8/8/8/8/PPPPPPPP/RQBBKNNR w KQkq - 0 1" has a standard position number everywhere. What do you think?

[dkappe]

Larry: I'm thinking of asking Lucas if he can add this as an option to the 'Initial Position' screen of his program but before that it might make sense to have a standard, common list of positions each with its own code so that, for example "rbbqknnr/pppppppp/8/8/8/8/PPPPPPPP/RQBBKNNR w KQkq - 0 1" has a standard position number everywhere. What do you think?

The fen’s I put on github are alphabetically sorted. That’s certainly a consistent, reproducible ordering.

[Chessqueen]

Why reduce the number of possibilities making it easier to prepare openings.
I would say that the old proposition of Chess2880 where there is no castling and the only rule for the pieces is that the bishops must be on different colours is much better.
More possibilities and randomness, no special rules and any engine that can take a FEN input can play it.

I have for many years wondered why people are so hung up on castling that they even had to implement it in Chess960.

Best regards
anst

The point is not to reduce the number of possibilities, it is that the symmetrical positions such as the 2880 in chess2880 are too drawish when the opponents are (or use, as in correspondence play) top engines. Also chess324 is just much more like normal chess with normal castling rules. Of course I could dramatically increase the number of positions by letting the king be anywhere, forfeiting castling when not on e1 or e8, but then hundreds of the positions would be surely winning for one side or the other. It is just a lucky break that chess324 leads to many positions approaching the win/draw line, but probably none clearly/significantly beyond it. I doubt that any other simple rule will produce this desirable consequence.

Another possibility to increase the amount of positions, since 85% of the times castling is done on the side of the King 0-0 or King's side is to only have the King and Rook on the side of the King in its original position and the other Rook can be placed anywhere. But 324 positions is plenty for us humans to handle and it is 323 more positions than the standard chess position, therefore, it is perfect. No need to make more positions.

[lkaufman]

Why reduce the number of possibilities making it easier to prepare openings.
I would say that the old proposition of Chess2880 where there is no castling and the only rule for the pieces is that the bishops must be on different colours is much better.
More possibilities and randomness, no special rules and any engine that can take a FEN input can play it.

I have for many years wondered why people are so hung up on castling that they even had to implement it in Chess960.

Best regards
anst

The point is not to reduce the number of possibilities, it is that the symmetrical positions such as the 2880 in chess2880 are too drawish when the opponents are (or use, as in correspondence play) top engines. Also chess324 is just much more like normal chess with normal castling rules. Of course I could dramatically increase the number of positions by letting the king be anywhere, forfeiting castling when not on e1 or e8, but then hundreds of the positions would be surely winning for one side or the other. It is just a lucky break that chess324 leads to many positions approaching the win/draw line, but probably none clearly/significantly beyond it. I doubt that any other simple rule will produce this desirable consequence.

Another possibility to increase the amount of positions, since 85% of the times castling is done on the side of the King 0-0 or King's side is to only have the King and Rook on the side of the King in its original position and the other Rook can be placed anywhere. But 324 positions is plenty for us humans to handle and it is 323 more positions than the standard chess position, therefore, it is perfect. No need to make more positions.

Probably if the queen's rook isn't fixed on its normal square, many of the positions will be winning for one side (mostly White). Also if the players can only castle short, it feels less like normal chess. I wouldn't mind increasing the number of positions if possible, but I don't think that there is any simple rule to accomplish this without allowing clearly winning positions. It is just good luck that we can get 324 positions this way without any being more favorable than the Grob is for Black. This is why it took so long to come up with this idea; it wasn't obvious that without symmetry there wouldn't be obviously won positions. I think the main reason is that with rooks in the corners and not bishops, there are no positions where White can immediately threaten to win material with his first move. This is what keeps White's advantage down to an acceptable (i.e. not clearly winning) advantage.

[hgm]

If there is a need for assigning numbers to the positions, I would recommend to use the same system as in Chess960. Where you first number the Bishop constellations 0-5, and then add 6 times the relative Queen location (0-2) on the remaining open squares. This can be done for white and black seeparately, and then you can take 18*white + black.

Advantage is that the position is easily reconstructable from the number. With alphabetical ordering of the FENs you might need the whole list for that.

[Michel]

The bishop constellations can be further factored as 3*2 (own color vs opposite color). So we can assign a code [0-2][0-1][0-2] which can be converted to a number if required.

[Michel]

Of course we need a code for white and black.

[Chessqueen]

If there is a need for assigning numbers to the positions, I would recommend to use the same system as in Chess960. Where you first number the Bishop constellations 0-5, and then add 6 times the relative Queen location (0-2) on the remaining open squares. This can be done for white and black seeparately, and then you can take 18*white + black.

Advantage is that the position is easily reconstructible from the number. With alphabetical ordering of the FENs you might need the whole list for that.

You are definitively correct. What a coincidence this must be week 324 ==>https://theweekinchess.com/html/twic324.html

[Chessqueen]

If there is a need for assigning numbers to the positions, I would recommend to use the same system as in Chess960. Where you first number the Bishop constellations 0-5, and then add 6 times the relative Queen location (0-2) on the remaining open squares. This can be done for white and black seeparately, and then you can take 18*white + black.

Advantage is that the position is easily reconstructible from the number. With alphabetical ordering of the FENs you might need the whole list for that.

You are definitively correct. What a coincidence this must be week 324 ==>https://theweekinchess.com/html/twic324.html

I thought that it was Friday the 13th April Fool, there are only 52 Weeks in a year, but nobody took my Joke seriously.

[Chessqueen]

There has been some discussion about how to improve chess960 (Fischerandom Chess) to address the fact that when top engines play against each other on good hardware at Rapid or slower time controls almost all the games end in draws, just as in normal chess (without forced unbalanced openings). Scrapping the symmetry requirement leads to some positions where one side is quite clearly winning.
I believe I have found a solution that is aesthetically pleasing, doesn't require special castling rules, and will dramatically lower draw percentages without any clearly won positions. I call it "Chess324". All rules are the same as in normal chess, including castling, only the start position is modified. The kings and rooks are placed on their normal positions. All the other pieces for White and Black are placed randomly, with no symmetry requirement, with the only restriction being that for each side the bishops must be on opposite colored squares. Unless I have miscalculated, there are 18 permutations for each side, making 324 total possible positions (including 18 symmetrical ones that are legal in chess960 of which 1 is the normal start position of chess).
In order to determine whether these positions are playable, I checked out the most promising-looking ones for White by checking whether White's advantage ever exceeds Black's advantage in normal chess after the Grob (1g4?) is played. There has been much discussion in the past over whether the Grob is losing or not, and I doubt that anyone really knows the answer; the Hiarcs database has Black winning 49% of the games, Lc0 gives Black 54% winning chance, and Stockfish and Dragon give evals suggesting that it is more likely to be a win than a draw but is very near the line. I checked all the promising positions I could think of with recent versions of Stockfish, Dragon, and Lc0, and in no case did I find one that produced an advantage larger than Black gets with the Grob (one position was tied per Lc0 but less per SF and Dragon). Of course the evals are all over the place, sometimes even Black is better, sometimes it's about even but not "balanced", sometimes one side is much better, but never clearly winning (at least not as clearly winning as the Grob as far as I was able to tell). Since many evals clearly favor one side, chess324 should be played in pairs of games, each side having White from the same position once. With humans, that's not essential, just recommended; with engines it would be necessary.
This version has huge advantages over chess960. First, no special castling rules, any engine or GUI or human can play with no instruction after seeing the initial position. Second, since all but 18 of the 324 positions are asymmetrical, opening play should be much more interesting and complex. Third, the normal positioning of the rooks and kings and normal castling makes the game feel closer to normal chess. Fourth, matches of up to 648 games can be played with no repeat positions, generally enough for most purposes. Most important, no matter how many cores or how much time the engines get, there should be plenty of decisive games for the foreseeable future since many positions are at least not too far from the win/draw line. The stronger engine will score 1.5 out of 2 in many of these positions for many years to come, unless chess is truly solved some day.
It is quite possible that a few of the initial positions may ultimately be judged to be won for White, but I am confident that even if they are "won", they will be near enough to the draw line to be playable with any current hardware or engines.

It seems weir or strange after human are used to play symmetrical position and suddenly have to play asymmetrical positions in some cases
[pgn][Event "Computer chess game"]
[Site "DESKTOP-OFQ3C0P"]
[Date "2022.08.13"]
[Round "1"]
[White "Dragon-2.6.1-64bit-avx2"]
[Black "Berserk-9-x64-avx2-pext"]
[Result "*"]
[BlackElo "3535"]
[Time "09:53:39"]
[WhiteElo "3550"]
[TimeControl "300+3"]
[SetUp "1"]
[FEN "rbbnknqr/pppppppp/8/8/8/8/PPPPPPPP/RBBNKQNR w KQkq - 0 1"]
[Termination "unterminated"]
[PlyCount "15"]
[WhiteType "program"]
[BlackType "program"]

1. e4 {(e2-e4 c7-c5 f2-f4 f7-f5 e4xf5 d7-d5 c2-c3 Nd8-c6 g2-g3 a7-a6 Ng1-f3
Bb8-a7 Qf1-e2 Bc8-d7 a2-a3 Nc6-a5 Nd1-e3 c5-c4 Bb1-c2 O-O-O Nf3-e5 d5-d4
Ne3xc4 Na5xc4 Qe2xc4+ Qg8xc4 Ne5xc4) +1.23/24 6} f6 {(f7-f6 d2-d4 d7-d5
e4xd5 Qg8xd5 c2-c3 Qd5-f7 Nd1-e3 Nf8-g6 Bb1-c2 c7-c6 Bc1-d2 Ng6-f4 h2-h4
Nf4-d5 Ne3-f5 Bb8-f4 O-O-O Bf4xd2+ Rd1xd2 Bc8-d7 Kc1-b1 Nd8-e6 Ng1-e2 g7-g6
Nf5-e3 Ne6-c7 Ne2-c1 O-O-O Qf1-e2 Nd5xe3 Qe2xe3 Qf7-e6 Qe3-g3 Nc7-d5
Qg3-f3) -0.82/23 6} 2. c3 {(c2-c3 c7-c6 Nd1-e3 e7-e5 Ng1-f3 Qg8-f7 d2-d4
e5xd4 c3xd4 Nf8-g6 Bc1-d2 b7-b6 Bb1-c2 a7-a5 Qf1-d3 O-O Qd3-a3 d7-d5 e4xd5
c6xd5 O-O-O Ng6-f4 g2-g3 Nf4-h3 Ne3xd5 Nh3xf2 Nd5-e7+ Kg8-h8 Ne7xc8)
+1.28/27 21} d5 {(d7-d5 e4xd5 Qg8xd5 d2-d4 Bc8-d7 Nd1-e3 Qd5-f7 a2-a4
Nf8-g6 f2-f4 e7-e6 Ng1-e2 O-O Qf1-f2 a7-a5 O-O Bb8-a7 f4-f5 Ng6-e7 f5xe6
Bd7xe6 Qf2-h4 f6-f5 Qh4-g3 c7-c6 Bb1-d3 Ba7-b8 Ne2-f4 Kg8-h8 Qg3-f2 Bb8xf4)
-0.90/25 27} 3. exd5 {(e4xd5 Qg8xd5 Nd1-e3 Qd5-f7 d2-d4 c7-c5 d4xc5 Nf8-d7
Bb1-c2 Nd7xc5 Qf1-b5+ Nc5-d7 b2-b3 Nd8-c6 Bc1-a3 Nd7-b6 Ng1-f3 Bc8-d7
Bc2-e4 O-O O-O-O Rf8-d8 Kc1-b1 Bb8-f4 Ba3-c5 f6-f5 Bc5xb6 a7xb6) +1.22/26
7} Qxd5 {(Qg8xd5 Nd1-e3 Qd5-f7 d2-d4 a7-a6 Ng1-f3 Nf8-g6 Qf1-e2 Ng6-f4
Qe2-d1 Qf7-h5 O-O O-O Rf1-e1 c7-c5 Bb1-e4 c5xd4 Nf3xd4 Qh5-c5 Qd1-b3+
Kg8-h8 Qb3-c4 Qc5-e5 Nd4-f3 Qe5-c7 Qc4xc7 Bb8xc7 g2-g3 Nf4-h3+ Kg1-g2)
-0.94/24 9} 4. Ne3 {(Nd1-e3 Qd5-f7 d2-d4 c7-c5 d4xc5 Nf8-d7 Bb1-c2 Nd7xc5
Qf1-b5+ Nc5-d7 b2-b3 Nd8-c6 Bc1-a3 a7-a6 Qb5-e2 O-O Ng1-f3 Nd7-e5 O-O-O
Qf7-h5 Ne3-d5 Bc8-f5 Ba3xe7 Bf5xc2 Qe2xc2 Rf8-e8 Nf3xe5 Nc6xe7) +1.23/27
12} Qf7 {(Qd5-f7 d2-d4 a7-a6 Ng1-f3 Nf8-g6 h2-h4 Ng6-f4 g2-g3 Nf4-d5 Qf1-e2
Nd5xe3 Qe2xe3 Qf7-e6 O-O Qe6xe3 Bc1xe3 Bc8-e6 Nf3-e1 c7-c6 Ne1-d3 Be6-d5
a2-a4 Bb8-d6 Bb1-c2 g7-g6 Rf1-e1) -0.66/23 8} 5. d4 {(d2-d4 c7-c5 d4xc5
Nf8-d7 Bb1-c2 Nd7xc5 Qf1-b5+ Nc5-d7 b2-b3 Nd8-c6 Bc1-a3 Nd7-b6 Ng1-f3
Bc8-d7 Bc2-e4 O-O O-O-O Rf8-d8 g2-g3 Bb8-c7 Rd1-d2 e7-e6 Rh1-d1 Bd7-e8
Qb5-e2 f6-f5 Be4-c2 Qf7-f6 Rd2xd8 Ra8xd8) +1.23/27 9} a6 {(a7-a6 Ng1-f3
Nf8-g6 a2-a4 Bc8-d7 Qf1-d3 Ng6-f4 Qd3-e4 c7-c5 O-O Bd7-c6 d4-d5 Bc6xd5
Ne3xd5 Qf7xd5 Qe4-c2 Nd8-e6 Rf1-d1 Qd5-c6 Bc1xf4 Ne6xf4 Qc2-e4 Qc6xe4
Bb1xe4 Ra8-a7 g2-g3 Nf4-e6 a4-a5 Bb8-c7 b2-b4 c5xb4 c3xb4 Ke8-f7 Be4-d5
Rh8-d8) -0.72/24 5} 6. Nf3 {(Ng1-f3 Bc8-d7 Qf1-e2 Nf8-g6 O-O Ng6-f4 Qe2-d1
c7-c6 Rf1-e1 Nd8-e6 Qd1-b3 Ne6-d8 c3-c4 O-O Bc1-d2 e7-e5 d4xe5 Bb8xe5
Ne3-f5 Kg8-h8 Nf3xe5 f6xe5 Re1xe5) +1.44/25 21} Ng6 {(Nf8-g6 a2-a3 Ng6-f4
Ne3-f5 c7-c6 Bc1xf4 Bb8xf4 Qf1-e2 g7-g6 Nf5-e3 Bc8-e6 O-O O-O Rf1-e1 Kg8-h8
a3-a4 a6-a5 Bb1-d3 Ra8-c8 Nf3-d2 Bf4-c7 Bd3-c4 f6-f5) -1.02/25 5} 7. h4
{(h2-h4 Bb8-a7 h4-h5 Ng6-f4 Bb1-c2 Bc8-e6 c3-c4 Be6-d7 d4-d5 Nf4xh5 Bc1-d2
e7-e5 O-O-O g7-g6 Qf1-e1 O-O Kc1-b1 Rf8-e8 g2-g4 Ba7xe3 g4xh5 Be3xd2 Nf3xd2
g6-g5 Nd2-e4 Kg8-h8 h5-h6) +1.55/26 19} Nf4 {(Ng6-f4 a2-a3 c7-c6 Bb1-c2
Nf4-d5 Bc1-d2 Nd5xe3 Bd2xe3 Qf7-h5 O-O-O Bc8-f5 Qf1-e2 Bf5xc2 Qe2xc2 O-O
Nf3-d2 b7-b5 Kc1-b1 Bb8-c7 Rh1-g1 Nd8-e6 g2-g4 Qh5-d5 h4-h5 f6-f5 g4xf5
Qd5xf5 h5-h6 Qf5xc2+ Kb1xc2 g7-g6 Rd1-e1 Ne6-f4 Nd2-e4 Nf4-d5 Ne4-c5)
-0.65/26 5} 8. Bc2 {(Bb1-c2 Bb8-a7 h4-h5 Bc8-e6 c3-c4 Be6-d7 d4-d5 Nf4xh5
Bc1-d2 e7-e5 O-O-O g7-g6 Qf1-e1 O-O Kc1-b1 Ba7xe3 f2xe3 Bd7-g4 e3-e4 Qf7-d7
Qe1-h4 Nd8-f7 Bd2-b4 g6-g5 Qh4-h2) +1.52/25 11} *[/pgn]