BugChess 2 bug

[Gábor Szots]

Look at this game:

[Event "Life below Rybka"]
[Site "Szentendre"]
[Date "2007.07.26"]
[Round "22"]
[White "BugChess2_V1_5"]
[Black "Hermann"]
[Result "1-0"]
[BlackElo "2200"]
[Time "19:06:05"]
[WhiteElo "2200"]
[TimeControl "40/360:40/360:40/360"]
[Termination "normal"]
[PlyCount "194"]
[WhiteType "program"]
[BlackType "program"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. a4 h6 8.
Nd5 Nxd5 9. exd5 Ne7 10. c3 Nf5 11. Bd3 g6 12. O-O Bg7 13. Bd2 {+0.22/10
12} O-O {-0.31/9 3} 14. Qb3 {+0.35/9 12} Kh7 {-0.31/9 7} 15. Rae1 {+0.37/9
12} Bd7 {-0.24/9 14} 16. Qa3 {+0.26/10 12} a6 {-0.09/10 7} 17. Nxd6
{+0.26/11 3} Nxd6 {-0.04/11 7} 18. Qxd6 {+0.32/11 4} Bxa4 {-0.11/10 4} 19.
Qxd8 {+0.25/11 13} Rfxd8 {-0.16/11 6} 20. c4 {+0.23/12 9} b5 {-0.24/11 13}
21. f4 {+0.30/11 13} exf4 {-0.21/10 7} 22. Rxf4 {+0.23/11 13} Ra7 {-0.17/10
22} 23. Ba5 {+0.02/10 13} Rdd7 {+0.09/10 6} 24. Bc3 {-0.15/11 13} Bb3
{+0.11/10 2} 25. cxb5 {-0.08/12 13} axb5 {+0.16/11 10} 26. Bxb5 {-0.10/12
13} Rxd5 {+0.17/11 6} 27. Rb4 {-0.15/11 13} Bc2 {+0.19/11 15} 28. Be8
{-0.16/10 13} Rc7 {+0.22/9 4} 29. Rf4 {-0.23/12 13} Kg8 {+0.24/9 3} 30.
Bxg7 {-0.05/12 13} Kxg7 {+0.21/11 4} 31. Rc1 {-0.08/13 13} f5 {+0.17/10 6}
32. Rf2 {0.00/14 13} Rd1 {+0.18/12 7} 33. Rxd1 {+0.03/14 7} Bxd1 {+0.15/13
3} 34. b4 {0.00/13 14} Rc8 {+0.08/12 7} 35. Bd7 {+0.11/14 14} Rd8 {0.00/13
13} 36. Bc6 {+0.15/13 14} Rd4 {-0.09/13 27} 37. Rb2 {+0.28/13 14} Rd6
{-0.23/12 15} 38. b5 {+0.78/15 11} Ba4 {-0.44/12 9} 39. Rb4 {+1.23/15 16}
Bd1 {-0.61/12 16} 40. b6 {+4.27/16 16} Rd8 {-5.07/13 82} 41. b7 {+4.38/15
8} Rb8 {-5.10/13 6} 42. Rb2 {+4.43/14 8} Kf8 {-5.25/14 7} 43. Ra2 {+4.70/17
8} Kg7 {-5.50/15 46} 44. Ra8 {+4.79/15 8} Rxb7 {-5.52/14 8} 45. Bxb7
{+4.80/13 8} Bb3 {-5.51/13 10} 46. Bf3 {+4.83/13 9} Bf7 {-5.52/13 11} 47.
h4 {+4.85/13 8} g5 {-5.41/13 7} 48. Ra5 {+4.98/13 8} Kf6 {-5.48/14 19} 49.
hxg5 {+4.98/13 8} hxg5 {-4.98/13 5} 50. g4 {+4.98/14 8} Be6 {-4.44/14 5}
51. gxf5 {+5.02/14 8} Bxf5 {-4.55/15 7} 52. Kh2 {+5.02/14 8} Be6 {-4.64/15
6} 53. Kg3 {+5.02/14 9} Bf5 {-4.70/15 5} 54. Ra6 {+5.04/13 8} Ke7 {-4.73/14
5} 55. Bd5 {+5.03/14 8} Bc8 {-4.82/12 5} 56. Rh6 {+5.05/14 9} Bf5 {-4.83/14
19} 57. Rb6 {+5.03/14 8} Kd8 {-4.83/15 6} 58. Rf6 {+5.14/13 8} Bd7
{-4.85/15 4} 59. Rf7 {+5.14/15 8} Ke8 {-4.89/15 5} 60. Rg7 {+5.14/13 8} Kd8
{-4.97/15 7} 61. Kg2 {+5.14/14 8} Bg4 {-4.97/15 7} 62. Kh2 {+5.14/13 11}
Bd7 {-4.90/14 8} 63. Kg3 {+5.15/14 8} Ke8 {-4.97/15 10} 64. Kf2 {+5.14/12
8} Ba4 {-4.99/14 15} 65. Rc7 {+5.14/12 8} Bd1 {-4.88/12 5} 66. Ke1
{+5.15/12 8} Bh5 {-4.89/13 4} 67. Rb7 {+5.15/13 8} Bg4 {-4.85/13 8} 68. Bf7
{+5.13/13 8} Kd8 {-4.75/13 3} 69. Bd5 {+5.14/13 8} Ke8 {0.00/29 2} 70. Rc7
{+5.14/13 8} Bh5 {0.00/28 3} 71. Rh7 {+5.14/13 8} Bg6 {-4.85/13 4} 72. Rb7
{+5.14/13 8} Bf5 {-4.85/13 3} 73. Kf2 {+5.15/13 8} Bd7 {-4.82/13 4} 74. Ra7
{+5.15/13 8} Kd8 {-4.81/13 4} 75. Kf3 {+5.15/12 8} Bf5 {-5.03/13 5} 76. Bc6
{+5.15/12 8} Kc8 {-4.98/13 10} 77. Bb5 {+5.14/13 8} Kd8 {-4.99/14 8} 78.
Ba4 {+5.15/13 8} Kc8 {-5.01/13 16} 79. Bc6 {+5.15/12 8} Bc2 {-5.01/13 14}
80. Kg4 {+5.22/12 9} Bd3 {-8.34/16 38} 81. Re7 {+5.17/12 8} Bc2 {-8.34/15
6} 82. Rg7 {+5.22/12 8} Kb8 {-M12/16 34} 83. Bd7 {+5.36/14 8} Be4 {-8.21/15
7} 84. Be6 {+5.36/14 8} Bb7 {-8.32/16 6} 85. Rd7 {+5.36/13 8} Bc6 {-8.25/15
7} 86. Rf7 {+5.22/13 8} Bb7 {-8.34/16 7} 87. Bf5 {+5.22/12 8} Bg2 {-8.32/16
5} 88. Kg3 {+5.18/13 8} Bf1 {-8.15/12 5} 89. Rg7 {+5.05/12 8} Be2 {-8.11/14
5} 90. Kf2 {+5.06/13 9} Bc4 {-8.28/14 8} 91. Ke3 {+5.07/14 8} Ba6 {-8.45/15
8} 92. Kd4 {+8.31/12 8} Bc8 {-M8/14 5} 93. Rg8 {+8.80/14 8} Kc7 {-M7/13 6}
94. Rxc8 {+8.90/12 8} Kd6 {-M6/12 6} 95. Bg4 {+M1/11 3} Ke7 {-M5/8 0} 96.
Ke5 Kf7 {-M4/6 0} 97. Rc7 Kg8 {-M3/47 5 Black resigns} 1-0

I thought the game was going to end in a draw. It looks to me that Bug found the win accidentally. Why was the g5 pawn a taboo?

I have the log file too, but I did not want to paste 300 more lines into this message.

[Graham Banks]

Hi Gabor,

yes, Francois is aware of the bug and would love to have any log files you've produced. Let me know if you don't have his email address.

Regards, Graham.