Author: Janos Keinrath
Date: 01:03:57 10/19/03
Go up one level in this thread
On October 18, 2003 at 18:21:15, Dieter Buerssner wrote:
>On October 18, 2003 at 14:10:03, Kurt Utzinger wrote:
>
>> The position is a draw even if Black loses the b3-pawn.
>> And it's rather difficult for Black to play faulty moves.
>
>Might be true for strong chess players. I doubt, that it is true for many rather
>strong chess engines. Here is a game, that was played from Dan's position. On
>P4, 2.53 GHz. Both engines had 100 MB hash. I played it manually for the side of
>Yace (so I decided about the time to think). I believe similar games could
>happen in automatic play. Ponder was on (both engines got about similar CPU time
>- I checked this).
>
>[Event "Computer chess game 40 moves in 2 h"]
>[Site "?"]
>[Date "2003.10.17"]
>[Round "1"]
>[White "Yacex, manual"]
>[Black "Shredder 6"]
>[Result "1-0"]
>[SetUp "1"]
>[FEN "8/2b4p/k1p1p3/1pP1P1pP/4K1P1/PpB5/1P6/8 w - -"]
>
>1. Kd4 Bd8 {-1.86/23 5:29m} 2. Bd2 {1:04m} h6 {-1.63/22
>3:21m} 3. Kd3 {15s} Be7 {-1.94/22 4:56m} 4. Bb4 {3s} Bf8
>{-1.31/26 4:07m} 5. Kc3 {5s} Bg7 {-1.51/26 1:52m} 6. Kxb3
>{2s} Bxe5 {-1.36/22 41s} 7. Bc3 {40s} Bxc3 {-1.02/24 2:30m}
>8. Kxc3 {4s} Ka5 {-0.89/26 3:02m} 9. Kd4 {3s} Ka4 {-0.89/25
>2:29m} 10. Ke5 {5s} Kb3 {-0.89/24 5:32m} 11. Kd6 {2:37m} e5
>{-0.89/23 4:12m} 12. Kxc6 {3s} e4 {-0.88/21 4:32m} 13. Kxb5
>{4s} e3 {-0.94/20 4:15m} 14. c6 {2s} e2 {-0.91/14 7s}
>15. c7 {2s} e1=Q {-0.84/14 12s} 16. c8=Q {6s} Qe2+
>{-0.92/13 3:50m} 17. Kb6 {8s (Kc6)} Kxb2 {-0.93/14 4:15m}
>18. a4 {4s} Qe3+ {-0.85/13 3:23m} 19. Kc7 {7:59m (Qc5)}
>Qf4+ {-1.03/14 2:36m} 20. Kd8 {2s} Qxa4 {-1.03/14 3:15m}
>21. Ke7 {6s} Qf4 {-1.26/15 5:14m} 22. Qh8+ {10:30m (Qf5)}
>Ka3 {-1.47/14 7:00m} 23. Qxh6 {11:21m} Qxg4 {-1.81/14 0s}
>24. Qd6+ {21:20m} Ka4 {-1.94/14 0s} 25. Qc6+ {12:18m} Kb4
>{-2.63/14 0s} 26. h6 {21s} Qf5 {-2.63/13 6:07m} 27. Qd6+
>{4:08m (Kd6)} Ka5 {-2.55/10 16s} 28. Qa3+ {7:15m} Kb5
>{-3.17/14 46s} 29. Qb3+ {1:03m} Ka5 {-3.47/13 7:13m}
>30. Qf7 {3s} Qe5+ {-3.47/13 5:30m} 31. Qe6 {4s} Qh8
>{-3.24/14 4:58m} 32. Qf5+ {9s} Ka4 {-3.48/12 1:28m} 33. h7
>{43s} Ka3 {-9.53/12 1:58m} 34. Qd3+ {12s} Kb4 {-10.69/12
>5:15m} 35. Kf7 {15s (Qg6)} g4 {-11.06/12 3:33m} 36. Kg6
>{49s (Qg6)} Qe8+ {-M45/9 1:24m} 37. Kg5 {1:28m} Qe5+
>{-M44/13 0s} 38. Kxg4 {24s} Qg7+ {-M43/4 0s} 1-0
>
6..Bxe5 was a mistake. If Black keeps the position blocked and moves
only Bf8-g7 the game is draw.
The bishop holds the king side pawns and the king can hold the queen side.
>
>BTW. I think the pawn endgame and the Q-endgame that appeared in this experiment
>might be rather interesting. White got for example KQPKQP for a while, which
>probably was won all the time (but perhaps not trivial).
>
>
>Another line, that could happen:
>1. Kd4 Bd8 2. Bd2 h6 3. Kd3 b4 4. axb4 Kb5 5. Kc3 Bc7 6. Kxb3 Bb8 7. Kc3
In my opinion the bishop is useless at b8, it has to guard the kings side
pawns from e7,f8 or g7.
After 5... Be7 6.Kxc3 Bd8 and draw. White can't make any progress, the
paws blocked and the only breaktrough point, g5 is defended.
>
>[D] 1b6/8/2p1p2p/1kP1P1pP/1P4P1/2K5/1P1B4/8 b - -
>
>And now, for a long time, many chess engines might chose Bxe5?, which (I think)
>will lose the game.
>
>This might be a good test position for engines. How long does your engine need
>to avoid Bxe5. I belive (but I am not sure) that Bc7 will draw, while Bxe5 will
>lose.
>
>To summarize: At least for chess engines "And it's rather difficult for Black to
>play faulty moves." seems wrong. But I agree, that the position should be draw
>(I really don't have the expertize to judge this as a chess player, but I came
>to this conclusion by analyzing with my engine).
>
>Regards,
>Dieter
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