Interesting position (wrong adjudication)

[Naum]

This position came up in a game between Crafty and Naum:

8/4PR2/3N2k1/8/4r1Kp/8/8/8 w - - 0 87

Game was adjudicated as a win for white, because both engines had scores higher then 7, but in fact it seems to be a dead draw.

Black will just keep moving his rook on the e-file, and white can move only his king without losing a piece. There is no way for white king to approach his pawn.

Shredder gives a score of 9.5!

This is an extreme case, but I noticed many games with +5 score that end up being drawn, so +7 is probably a minimum that should be used.

Regards,
Alex

[Igor Gorelikov]

Yes, it is a known issue. Even 7 pawns are not safe for adjudication.
But for engine tests with many games you may use 6 pawns because such cases are very rare (within statistical eror).

Igor

[Pedro Castro]

my engine in some occasions with king and queen against king and pawns on seven row haved an advantage of I create to remember of 8-9 points it has not been able to win in some occasion, at least in fast games, really not if they were draw or no.

[Anonymous]

Yes, it is a known issue. Even 7 pawns are not safe for adjudication.
But for engine tests with many games you may use 6 pawns because such cases are very rare (within statistical eror).

I agree. It is clear, that for most tournament, the TDs want engines to resign (and not only with scores > 10). For tournaments, where I started personally (more or less), I setup Yace to never resign. In CCT tournaments the games are played automatically, so it does not hurt, to let them play it out, either (with the current time control used). In the Paderborn tournament, where the engine has to be operated manually, the operator can resign, when it is really clear. I would feel a bit stupid, when the engine resigned in a draw position.

Another position from a human game:

8/8/6p1/6Q1/2K4p/6kP/5p2/8 b - - 0 55

My engine shows +8 no problem to draw the position.

Regards,
Dieter

[Event "?"]
[Site "Beersheba ,CBM 09"]
[Date "1988.??.??"]
[Round "?"]
[White "Kortchnoi, V."]
[Black "Rechlis, G."]
[WhiteElo "2640"]
[BlackElo "2475"]
[ECO "A15"]
[Result "1/2-1/2"]

1. Nf3 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. g3 Bg7 6. Bg2
O-O 7. O-O c5 8. Qa4 Nc6 9. Qc4 Nxc3 10. bxc3 b6 11. Qh4
Bb7 12. Rb1 e6 13. c4 Qxh4 14. Nxh4 Rab8 15. Nf3 Nb4
16. Bb2 Rfd8 17. Bxg7 Kxg7 18. Rb2 Rd6 19. d3 Re8 20. a3
Na6 21. Ra1 e5 22. Nd2 Bxg2 23. Kxg2 f5 24. a4 Nb4 25. a5
Re7 26. f3 h5 27. h3 Kf6 28. axb6 axb6 29. Ra8 Rdd7 30. Rb1
Ra7 31. Ra1 Nc6 32. Nb1 Rxa1 33. Rxa1 Ra7 34. Rxa7 Nxa7
35. Nc3 Ke6 36. Nd5 b5 37. Nc7+ Kd7 38. Nxb5 Nxb5 39. cxb5
Kc7 40. f4 exf4 41. gxf4 h4 42. Kf2 Kb6 43. Ke3 Kxb5
44. Kd2 Kb4 45. Kc2 c4 46. Kb2 cxd3 47. exd3 Kc5 48. Kc3
Kd5 49. d4 Ke4 50. Kc4 Kxf4 51. d5 Kg3 52. d6 f4 53. d7 f3
54. d8=Q f2 55. Qg5+ 1/2-1/2