AntiSymmetry FractalChess ExtremeRuleSet(Stockfish playable)
Posted: Sun May 03, 2015 10:00 pm
This is a special setup for chess. Tournament players play it using Stockfish almost only. The goal is to make correspondence and advanced chess more playable by introducing little adjustments while preserving everything "chess". Top-level correspondence and advanced chess are way too drawish. Three concepts were developed to overcome this without creating really new chess variant.
Fractal Chess
Random960 Fisher chess looks drawish too as well. We checked it in test tournament with experienced players using some positions from Fisher 960 chess. The problem is that initial position is too equal for both sides. With current software and hardware, good player can keep equality all over the game to draw end. In Fractal Chess initial position is selected according to computer value of it. The initial value should not be near zero, position should advantage for one side, like 0.30-0.50 That way value could evolve to infinity (winning) or zero. It is like point of bifurcation that could turn either way. And slightest differences do matter.
It is like fractal processes, wherein near points could have different attractors.
Anti-Symmetry
To keep initial position's style similar to classic position, only positions with some sort of internal symmetry are allowed. Also a few additional rules applied in order to keep internal harmony of the position. Bishops could be only on c1,d1,e1,f1 squares, knights are not cornered. However, black's and white's starting position could be different. That way kings are often located at different sides, which makes play sharp. Castle is not allowed. (it is encoded into start fen code)
There are about 6 such initial positions from Chess960, that way 72 possible starting positions are available for Anti-Symmetry. There are also some positions that are not into Chess960 possible in Anti-Symmetry.
rnbqnbkr/pppppppp/8/8/8/8/PPPPPPPP/RKBNQBNR w - - 0 1
Knights and bishops have symmetrical positions relative to king.
rqnbbnkr/pppppppp/8/8/8/8/PPPPPPPP/RKNBBNQR w - - 0 1
Pieces mirror over center.
rnqbbknr/pppppppp/8/8/8/8/PPPPPPPP/RNKBBQNR w - - 0 1
Pieces mirror over center.
rqbnnbkr/pppppppp/8/8/8/8/PPPPPPPP/RKBNNBQR w - - 0 1
Pieces mirror over center.
rnbqnbkr/pppppppp/8/8/8/8/PPPPPPPP/RKBNQBNR w - - 0 1
Knights and bishops mirror over queen.
qrbnkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBKNBRQ w - - 0 1
Knights, bishops and rooks mirror over king.
Positions with initial value from 0.30 to 0.50 or more are selected for Fractal Chess.
Extreme rule set
It is extended victory conditions.
1) stalemate is win for stronger side
2) knight+king on bishop+king vs alone king is win for stronger side (3 move rule to keep extra piece applied)
While this is not incorporated into stockfish, correspondence chess players used manual analysis in rare cases. More important was actually middle game adjustments to avoid worse endgames. Cause in correspondence chess endgames tend to be either totally won or totally drawish and stalemate rule does not add much to endgames. However, with 7% of actual decisive games in typical top correspondence chess tournaments any anti draw rule could add value.
One can play Anti-Symmetry Fractal chess with out Extreme rule set like Stockfish in test games did.
100+ correspondence games were completed with extreme rule set from different starting positions.
Also win or loss rule was introduced. Draw counts as win for black side. In top correspondence advanced chess black wins are rare, and with such a strong initial advantage they are almost unlikely. However, white side could exploit any possible risky variant without danger of losing some points.
That way Fractal chess becomes two result game. Win of stronger side or successful defense. In fact, it is typical for top advanced chess to equalize with black and make a draw anyway.
Test tournament demonstrated increase of percentage of decisive games.
In this position
rnqbbknr/pppppppp/8/8/8/8/PPPPPPPP/RNKBBQNR w - - 0 1
with initial value +0.35
white won 50% of games and black defended in 50% of games.
Also matches with long time controls among Stockfishes (in Anti-Symmetry Fractal Chess) showed irregular results too.
Fractal Chess
Random960 Fisher chess looks drawish too as well. We checked it in test tournament with experienced players using some positions from Fisher 960 chess. The problem is that initial position is too equal for both sides. With current software and hardware, good player can keep equality all over the game to draw end. In Fractal Chess initial position is selected according to computer value of it. The initial value should not be near zero, position should advantage for one side, like 0.30-0.50 That way value could evolve to infinity (winning) or zero. It is like point of bifurcation that could turn either way. And slightest differences do matter.
It is like fractal processes, wherein near points could have different attractors.
Anti-Symmetry
To keep initial position's style similar to classic position, only positions with some sort of internal symmetry are allowed. Also a few additional rules applied in order to keep internal harmony of the position. Bishops could be only on c1,d1,e1,f1 squares, knights are not cornered. However, black's and white's starting position could be different. That way kings are often located at different sides, which makes play sharp. Castle is not allowed. (it is encoded into start fen code)
There are about 6 such initial positions from Chess960, that way 72 possible starting positions are available for Anti-Symmetry. There are also some positions that are not into Chess960 possible in Anti-Symmetry.
rnbqnbkr/pppppppp/8/8/8/8/PPPPPPPP/RKBNQBNR w - - 0 1
Knights and bishops have symmetrical positions relative to king.
rqnbbnkr/pppppppp/8/8/8/8/PPPPPPPP/RKNBBNQR w - - 0 1
Pieces mirror over center.
rnqbbknr/pppppppp/8/8/8/8/PPPPPPPP/RNKBBQNR w - - 0 1
Pieces mirror over center.
rqbnnbkr/pppppppp/8/8/8/8/PPPPPPPP/RKBNNBQR w - - 0 1
Pieces mirror over center.
rnbqnbkr/pppppppp/8/8/8/8/PPPPPPPP/RKBNQBNR w - - 0 1
Knights and bishops mirror over queen.
qrbnkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBKNBRQ w - - 0 1
Knights, bishops and rooks mirror over king.
Positions with initial value from 0.30 to 0.50 or more are selected for Fractal Chess.
Extreme rule set
It is extended victory conditions.
1) stalemate is win for stronger side
2) knight+king on bishop+king vs alone king is win for stronger side (3 move rule to keep extra piece applied)
While this is not incorporated into stockfish, correspondence chess players used manual analysis in rare cases. More important was actually middle game adjustments to avoid worse endgames. Cause in correspondence chess endgames tend to be either totally won or totally drawish and stalemate rule does not add much to endgames. However, with 7% of actual decisive games in typical top correspondence chess tournaments any anti draw rule could add value.
One can play Anti-Symmetry Fractal chess with out Extreme rule set like Stockfish in test games did.
100+ correspondence games were completed with extreme rule set from different starting positions.
Also win or loss rule was introduced. Draw counts as win for black side. In top correspondence advanced chess black wins are rare, and with such a strong initial advantage they are almost unlikely. However, white side could exploit any possible risky variant without danger of losing some points.
That way Fractal chess becomes two result game. Win of stronger side or successful defense. In fact, it is typical for top advanced chess to equalize with black and make a draw anyway.
Test tournament demonstrated increase of percentage of decisive games.
In this position
rnqbbknr/pppppppp/8/8/8/8/PPPPPPPP/RNKBBQNR w - - 0 1
with initial value +0.35
white won 50% of games and black defended in 50% of games.
Also matches with long time controls among Stockfishes (in Anti-Symmetry Fractal Chess) showed irregular results too.