Yet another Fruit post: illegal moves

[Volker Pittlik]

Geschrieben von: / Posted by: Volker Pittlik at 11 March 2004 13:26:50:

I was playing a little gauntlet with Fruit (executable from yesterday) at 3/3 time control. Fruit was using Bookthinker and UCI2WB. Everthing was working nice but I noticed some illegal moves by Fruit.
In this position


Fruit is in check but played 34...h4 what is illegal.
Something similar happend in this position: 8/8/4k3/4r1p1/4P3/4RK2/8/8 b - - 23 87
Fruit moved its (black) pawn 2 squares backwards to the start position.
In this game:
[Event "Fruit"]
[Site "VPITTLIK"]
[Date "2004.03.10"]
[Round "4"]
[Number "44"]
[White "Mint"]
[Black "Fruit"]
[Result "0-1"]
[TimeControl "180+3"]
1. d3 d5 2. g3 e5 3. Nf3 Nc6 4. Nbd2 Nf6 5. Bg2 Be7 6. c4 O-O 7. cxd5 Qxd5
8. O-O Qb5 9. b3 Bg4 10. Nc4 Bxf3 11. Bxf3 Nd4 12. Bg2 Rad8 13. e3 Nc6 14.
a4 Qa6 15. Qe2 Nd5 16. Qh5 Ndb4 17. Be4 g6 18. Qe2 f5 19. Bxc6 Nxc6 20. Bb2
Rfe8 21. Nxe5 Nxe5 22. Bxe5 Qxd3 23. Qa2 c5 24. Rac1 Qd5 25. Qb2 Bg5 26.
Bc3 Rxe3 27. fxe3 Bxe3+ 28. Rf2 Bxc1 29. Qxc1 Qxb3 30. Qe3 Qd1+ 31. Rf1 Qd6
32. Re1 b6 33. Qe2 Kf7 34. a5 Kg8 35. axb6 axb6 36. Qa6 Kf8 37. Bh8 Kg8 38.
Bc3 Kf8 39. Bh8 g8xh8 40. Rb1 Qd4+ 41. Kf1 Qe4 42. Qxb6 Qh1+ 43. Kf2 Qxh2+
44. Kf1 Qh1+ 45. Kf2 Rd2+ 46. Ke3 Qh6+ 47. Kf3 Qh5+ 48. Ke3 Qg5+ 49. Kf3
Qg4+ 50. Ke3 Qd4+ 51. Kf3 Rf2#
{Black wins on time} 0-1
39...g8xh8 is completely nonsense because g8 is empty. But both programs continued to play !
In all 4 games against Ruffian 210 Fruit was checkmated but the programs didn't care and Ruffian won on time instead.
All logs and PGN are available on request.

Regards
Volker

[Fabien Letouzey]

Geschrieben von: / Posted by: Fabien Letouzey at 11 March 2004 13:57:11:
Als Antwort auf: / In reply to: Yet another Fruit post: illegal moves geschrieben von: / posted by: Volker Pittlik at 11 March 2004 13:26:50:

I was playing a little gauntlet with Fruit (executable from yesterday) at 3/3 time control. Fruit was using Bookthinker and UCI2WB. Everthing was working nice but I noticed some illegal moves by Fruit.

Volker,
Surely you understand my slight suspicion when you mention that UCI2WB was used
So unfortunately I am going to ignore this problem until somebody mentions a similar one without UCI2WB. I don't want to spend time looking for a bug that might be somewhere else.
Just thinking ... A problem? Do I hear "log files"?
If these positions are "pasted" as FEN, I don't think Fruit is going to play these illegal moves, my point is that this is exactly the way UCI is working. The engine is "pasted" positions and asked to search.
Thanks anyway, I will keep my guard up.
Fabien.