An unexpected perpetual check

[Telmo Escobar]

Geschrieben von:/Posted by: Telmo Escobar at 30 June 2004 20:23:19:


In the following game Crafty 17.14 SMP gave a perpetual in an easily won position. The game was played in CM 8000 GUI. Any idea about what happened?
Telmo
[Event "Engine Tournament"]
[Site "Athlon-1200"]
[Date "2004.6.30"]
[Round "11"]
[White "Chessmaster 8000"]
[Black "Crafty 17.14 SMP"]
[Result "1/2-1/2"]
[TimeControl "3600"]
1. Nf3 Nf6 2. d4 e6 3. c4 b6 4. g3 Ba6 5. b3 Bb4+ 6. Bd2 Be7 7. Bg2 c6 8.
Bc3 d5 9. Ne5 Nfd7 10. Nxd7 Nxd7 11. Nd2 O-O 12. O-O Rc8 13. e4 b5 14. Re1
dxe4 15. Nxe4 bxc4 16. Qe2 c5 17. dxc5 Nxc5 18. Qg4 g6 19. Nxc5 Rxc5 20.
Rad1 Qb8 21. b4 Rf5 22. a3 Qc7 23. Be4 Rg5 24. Qe2 Bb5 25. Bg2 Ba4 26. Rc1
Bb3 27. Qb2 Rc8 28. Re3 Qd7 29. Re2 Rb5 30. Rce1 Qc7 31. Re3 Rd8 32. Bh8
Bf8 33. Bf6 Rd7 34. Bc3 Bh6 35. f4 Bf8 36. Kh1 h6 37. Bf1 Rbd5 38. Bg2 Rd1
39. Bf3 Rxe1+ 40. Rxe1 Ba4 41. Kg1 Qb6+ 42. Kf1 Bc6 43. Bxc6 Qxc6 44. Qg2
Qd5 45. Kg1 Qd3 46. Qb2 Qf3 47. Bd4 Qd5 48. Bc3 a5 49. Rf1 axb4 50. axb4
Qe4 51. Qf2 Rb7 52. Rd1 Bxb4 53. Rd8+ Bf8 54. Qd2 f5 55. Qd6 Rf7 56. Be5
Qd5 57. Rxf8+ Rxf8 58. Qe7 Qd1+ 59. Kg2 Qe2+ 60. Kh3 Qg4+ 61. Kg2 Qe2+ 62.
Kh3 Qg4+ 63. Kg2 Rf6 64. Qe8+ Kh7 65. Kf2 Qd1 66. Qe7+ Kg8 67. Qxf6 Qc2+
68. Ke1 Qc1+ 69. Ke2 Qc2+ 70. Kf1 Qd1+ 71. Kg2 Qe2+ 72. Kh3 Qg4+ 73. Kg2
Qe2+ 74. Kh3 Qg4+ 75. Kg2 Qe2+
1/2-1/2
{the standings in this tourney -after 11 rounds- are as follows:
The King 3.12d 8
Crafty 17.14 SMP 7.5
Ruffian 1.0.1 6.5
Pharaon 2.62 6
Ktulu 4.2 5
WB Nimzo 2000b 4.5
Yace Paderborn 3.5
Sjeng 12.13 3
The King has been defeated twice by the tail ender, Sjeng 12.13}