CCRL-FRC, Illegal move by Rybka

[Volker Annuss]

Hello,

in CCRL-404FRC there is a game with an illegal move by Rybka, but the game continued and Rybka got a point.

Greetings
Volker



Illegal move 30. ... Ka8


[Event "CCRL 404FRC"]
[Site "CCRL"]
[Date "2007.08.23"]
[Round "?"]
[White "Naum 2.2"]
[Black "Rybka 2.3.2"]
[Result "0-1"]
[WhiteElo "2891"]
[BlackElo "2977"]
[PlyCount "222"]
[SetUp "1"]
[FEN "rbbknqrn/pppppppp/8/8/8/8/PPPPPPPP/RBBKNQRN w GAga -"]

1. Ng3 Ng6 2. d4 d5 3. Nf3 c6 4. c3 Bg4 5. h3 Bxf3 6. exf3 Nf6 7. Bxg6 hxg6 8.
Qd3 Kc8 9. O-O Bd6 10. c4 dxc4 11. Qxc4 Bxg3 12. fxg3 e6 13. Bd2 Nd5 14. b4 a6
15. a4 Nb6 16. Qd3 Qd6 17. Bf4 Qxb4 18. Rfb1 Qc4 19. Qe4 Nd5 20. Qe5 Nxf4 21.
Qxf4 f6 22. Rc1 Qd5 23. Rc5 g5 24. Qe3 Qd6 25. Rb1 Rd8 26. Kh2 Rd7 27. Rc4 Kd8
28. a5 Rc8 29. Rb6 Rcc7 30. Qd3 Ka8 31. Qc3 Qe7 32. Rc5 Qd8 33. Rb4 Rd6 34. Qe3
Rcd7 35. Rb2 Rxd4 36. Qxe6 Re7 37. Qb3 Rd1 38. Rb1 Rxb1 39. Qxb1 Re2 40. Qc1
Qd3 41. Rc3 Qd5 42. Ra3 Qd4 43. Qf1 Qd2 44. Qg1 Kb8 45. Ra1 Kc8 46. Kh1 Re5 47.
Qa7 Rxa5 48. Qa8+ Kc7 49. Rxa5 Qxa5 50. Qf8 Qe5 51. Qxg7+ Kb6 52. Qg8 c5 53.
Kh2 Ka7 54. Qf7 a5 55. Qa2 b6 56. f4 gxf4 57. gxf4 Qxf4+ 58. g3 Qe5 59. h4 Ka6
60. Kg2 b5 61. h5 c4 62. Qf2 Qg5 63. Qf3 Kb6 64. Qf2+ Kc6 65. Qe2 c3 66. h6
Qd5+ 67. Kf1 Qh1+ 68. Kf2 Qh2+ 69. Kf1 Qh1+ 70. Kf2 Qh2+ 71. Kf1 Qxh6 72. Qe6+
Kc5 73. Qf5+ Kd4 74. Qg4+ Ke5 75. Qe2+ Kd6 76. Qd3+ Ke7 77. Qe4+ Kf8 78. Qa8+
Kg7 79. Qb7+ Kh8 80. Qc8+ Kh7 81. Qd7+ Qg7 82. Qh3+ Kg8 83. Qc8+ Qf8 84. Qg4+
Kf7 85. Qh5+ Ke6 86. Qe2+ Kd5 87. Qd3+ Kc5 88. Qxc3+ Kb6 89. Qd4+ Ka6 90. Qd5
a4 91. Qc6+ Ka5 92. Qc7+ Kb4 93. Qf4+ Kb3 94. Qf5 Kc4 95. Qf4+ Kc5 96. Qc7+ Kd5
97. Qb6 Kc4 98. Qe6+ Kc5 99. Qe3+ Kc6 100. Qe4+ Kc7 101. Qd5 Qe8 102. Qd4 Qe5
103. Qa7+ Kc6 104. Qa8+ Kc5 105. Qc8+ Kb4 106. Qg4+ Ka5 107. Qf3 Qd6 108. Qa8+
Kb6 109. Qg8 b4 110. Qa2 Qc6 111. Kg1 b3 0-1

[Ray]

Thanks - Rybka does have some bugs and I've reported those to Vas. There are 2 time losses by Rybka also in the database, where Rybka just could not complete the game from that starting position. As a matter of interest I tried replaying them time and time again, and every time it lost on time. All is not well with this version, that is for sure.
I intend to run 64-bit engines now to add to the list, including a bug-fixed Rybka, and it may be wise to remove all games from this version completely.

[Ray]

Can I ask how you detected this ? In our normal chess databases, we do use a tool to detect and remove any games with illegal moves. But this tool does not work on FRC games as far as we know. Did you detect any others in the FRC database ?

[Volker Annuss]

Hello Ray,

Did you detect any others in the FRC database ?

Let me answer your last question first. I already reported here some weeks ago, that there are some illegal mate signs in the PGN database, but that is only a bug in the Shredder GUI.
When a move captures, gives check and leads to a position with insufficient material, there is a wrong mate sign. At the moment there are 6 such moves. You can load the PGN into notepad and replace all "# 1/2-1/2" by "+ 1/2-1/2" to fix this.

Can I ask how you detected this ?

After the first step you can use Hermann to check the PGN file for other errors.
- Start Hermann without GUI
- type "uci"
- type "book add <PGN file>" or "mat add <PGN file>". The first is faster.

You will get an error message, if there is something wrong. You will get nothing, when the file is OK. Hermann stops parsing the file after the first error, so it is a good idea to repeat the procedure after fixing an error.

Greetings
Volker

[Ray]

Thanks Volker - I will give this a try. To confirm, you think Rybka made an illegal move in just this one game ?

[Ray]

I gave it a try, it seems there is only one !