Author: Uri Blass
Date: 09:43:58 12/23/00
Go up one level in this thread
On December 23, 2000 at 09:59:54, James T. Walker wrote:
>On December 22, 2000 at 23:55:46, Uri Blass wrote:
>
>>On December 22, 2000 at 20:06:11, James T. Walker wrote:
>>
>>>I recently made the statement that Shredder was not a "Blitzer". I'm issuing a
>>>recall of that statement. I just finished a 20 game match of Gambit Shredder vs
>>>Chess Tiger 13 (G/5minutes). Gambit Shredder won +8 -6 =6 (11-9). That does
>>>not necessarily mean Gambit Shredder is better than Chess Tiger but it does
>>>indicate it can play with the Tiger. Below is game 17 of the match in which
>>>Gambit Shredder announced "Mate in 67". Of course it's a tablebase win in a
>>>very difficult KBBKN endgame.
>>
>>The question is if it is not a draw by the 50 move rule against the right
>>defence.
>>
>>There are 2 questions:
>>1)Can shredder win against itself(does it capture the knight early enough to
>>avoid a draw)?
>>
>>2)Is there a win for white against the right defence?
>>
>>The 2 questions are different because the best move for the side with the
>>bishops may be not the shortest way to force mate when you consider the 50 move
>>rule.
>>
>>I guess that you can answer only 1 because I do not know of a program that use
>>the right KBB vs KN tablebases of distance to conversion and not distance to
>>mate.
>>
>>Uri
>
>Here is the position and the "Autoplay" of Shredder 5. So I believe this
>answers the question. I think since Shredder captures the Knight on its 50th
>move the game is won even under the 50 move rule which is not a mandatory rule
>if I understand correctly. I believe if you are playing computer/computer games
>with tablebases involved you would wave the 50 move rule. The only reason for
>the 50 move rule in the first place is that humans could play on forever and not
>make progress. This does not apply to computers with tablebases. I made the
>diagram with black on the move since white has just captured the pawn. This
>does bring up the question of when to start the count if using the 50 move rule.
> I assume it starts on whites next move after the capture (move 2 below). The
>Knight is captured on the 50th move if my count is correct.
>Jim
>
>[D]8/6B1/8/8/1k6/8/K7/3B4 b - - Mate in 67 for white
>
>[Event "5 Minutes/game"]
>[Site "?"]
>[Date "2000.12.23"]
>[Round "?"]
>[White "Gambit Shredder"]
>[Black "Chess Tiger 13"]
>[Result "*"]
>[SetUp "1"]
>[FEN "8/2n4B/8/8/K2B1k2/8/8/8 b - -"]
>
>1... Ne6 {-M66/4 0s} 2. Bb2 {+M66/4 0s} Ng5 {-M65/4 0s}
>3. Bc1+ {+M65/4 0s} Kg4 {-M64/4 0s} 4. Bd3 {+M64/4 0s} Ne6
>{-M63/4 0s} 5. Kb5 {+M63/4 0s} Nf4 {-M62/4 0s} 6. Bc2
>{+M62/4 0s} Kf3 {-M61/4 0s} 7. Kc4 {+M61/4 0s} Ne6 {-M60/4
>0s} 8. Bb2 {+M60/4 0s} Nf4 {-M59/4 0s} 9. Kd4 {+M59/4 0s}
>Kf2 {-M58/4 0s} 10. Ke5 {+M58/4 0s} Kf3 {-M57/4 0s}
>11. Be4+ {+M57/4 0s} Kg3 {-M56/4 0s} 12. Kf5 {+M56/4 0s}
>Ng2 {-M55/4 0s} 13. Be5+ {+M55/4 0s} Kf2 {-M54/4 0s}
>14. Bc7 {+M54/4 0s} Ne1 {-M53/4 0s} 15. Bb6+ {+M53/4 0s}
>Kg3 {-M52/4 0s} 16. Bd5 {+M52/4 0s} Ng2 {-M51/4 0s} 17. Kg5
>{+M51/4 0s} Ne1 {-M50/4 0s} 18. Bc7+ {+M50/4 0s} Kf2
>{-M49/4 0s} 19. Kg4 {+M49/4 0s} Ke3 {-M48/4 0s} 20. Bb6+
>{+M48/4 0s} Kd3 {-M47/4 0s} 21. Bf7 {+M47/4 0s} Nc2 {-M46/4
>0s} 22. Bg6+ {+M46/4 0s} Kc3 {-M45/4 0s} 23. Ba5+ {+M45/4
>0s} Kb3 {-M44/4 0s} 24. Kf4 {+M44/4 0s} Nb4 {-M43/4 0s}
>25. Bf7+ {+M43/4 0s} Ka4 {-M42/4 0s} 26. Bb6 {+M42/4 0s}
>Kb5 {-M41/4 0s} 27. Be3 {+M41/4 0s} Kc6 {-M40/4 0s} 28. Ke5
>{+M40/4 0s} Nd3+ {-M39/4 0s} 29. Kd4 {+M39/4 0s} Nc5
>{-M38/4 0s} 30. Bd5+ {+M38/4 0s} Kb5 {-M37/4 0s} 31. Bf2
>{+M37/4 0s} Kb4 {-M36/4 0s} 32. Bf7 {+M36/4 0s} Nb3+
>{-M35/4 0s} 33. Ke4 {+M35/4 0s} Nc5+ {-M34/4 0s} 34. Kd5
>{+M34/4 0s} Na4 {-M33/4 0s} 35. Kd4 {+M33/4 0s} Nc5 {-M32/4
>0s} 36. Be1+ {+M32/4 0s} Kb5 {-M31/4 0s} 37. Kd5 {+M31/4
>0s} Nb3 {-M30/4 0s} 38. Be8+ {+M30/4 0s} Kb6 {-M29/4 0s}
>39. Kd6 {+M29/4 0s} Ka6 {-M28/4 0s} 40. Bd7 {+M28/4 0s} Kb6
>{-M27/4 0s} 41. Bc3 {+M27/4 0s} Ka6 {-M26/4 0s} 42. Bg4
>{+M26/4 0s} Kb5 {-M25/4 0s} 43. Be2+ {+M25/4 0s} Ka4
>{-M24/4 0s} 44. Bd1 {+M24/4 0s} Ka3 {-M23/4 0s} 45. Kd5
>{+M23/4 0s} Ka2 {-M22/4 0s} 46. Kc4 {+M22/4 0s} Nc1 {-M21/4
>0s} 47. Bg7 {+M21/4 0s} Ka3 {-M20/4 0s} 48. Kc3 {+M20/4 0s}
>Na2+ {-M19/4 0s} 49. Kc2 {+M19/4 0s} Ka4 {-M18/4 0s}
The last move is a big mistake.
Black can draw by the 50 move rule with 49...Nb4+
I think that the position with all the game is a good test position for chess
programs.
The main question is if the program can find 49...Nb4+ 50.Kb1 Nd5.
I am interesting if there is a program with tablebases that can find these
moves.
I suspect that a lot of programs are going to do Shredder's mistake(49...Ka4)
and I suspect that a lot of programs are going to play 50...Nc2 that is the only
losing move by the rules of chess after 49...Nb4+ 50.Kb1(the 50 move rule is one
of the rules).
Uri
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