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Subject: Re: Endgame easy test position

Author: Miguel A. Ballicora

Date: 12:58:55 09/18/01

Go up one level in this thread


On September 18, 2001 at 11:44:21, Uri Blass wrote:

>On September 18, 2001 at 10:31:10, Robert Hyatt wrote:
>
>>On September 18, 2001 at 09:40:26, Eduard Nemeth wrote:
>>
>>>First the game:
>>>
>>>[Event "TCh-YUG Herceg Novi YUG"]
>>>[Site "?"]
>>>[Date "2001.??.??"]
>>>[Round "?"]
>>>[White "Vukic,M"]
>>>[Black "Marinkovic,I"]
>>>[WhiteElo "2470"]
>>>[BlackElo "2440"]
>>>[ECO "A30"]
>>>[Result "1-0"]
>>>
>>>1. Nf3 Nf6 2. g3 b6 3. Bg2 Bb7 4. O-O g6 5. c4 c5 6. Nc3
>>>Bg7 7. d4 cxd4 8. Qxd4 d6 9. Be3 Nbd7 10. Rac1 Rc8 11. b3
>>>O-O 12. Qd2 Nc5 13. Rfd1 Nce4 14. Nxe4 Nxe4 15. Qe1 Qd7
>>>16. Nd4 Nf6 17. Nf3 Ne4 18. Qb4 Nc3 19. Rd2 Ne4 20. Rd3 Nc5
>>>21. Rdd1 Rfd8 22. Ne1 h5 23. Bxc5 Rxc5 24. Nd3 Bxg2
>>>25. Kxg2 Qb7+ 26. f3 Rc7 27. Nf2 Rdc8 28. Qd2 b5 29. cxb5
>>>Qxb5 30. Kf1 Bc3 31. Qd3 Qa5 32. Rc2 Bf6 33. Rdc1 Rxc2
>>>34. Rxc2 Rxc2 35. Qxc2 d5 36. e3 Kg7 37. Nd3 e6 38. Ke2 Qa3
>>>39. f4 Kg8 40. h3 Kg7 41. Kf3 Qd6 42. g4 hxg4+ 43. hxg4 e5
>>>44. fxe5 Bxe5 45. Nxe5 Qxe5 46. Qc5 Qf6+ 47. Kg3 Qe5+
>>>48. Kh3 a6 49. Qd4 Kf6 50. b4 Ke6 51. a4 Qc7 52. g5 Qc2
>>>53. Qf6+ Kd7 54. Qxf7+ Kd6 55. Qf6+ Kd7 56. Qd4 Ke6 57. Kg3
>>>Qb1 58. Qb6+ Ke7 59. Qb7+ Kf8 60. Qxd5 Qxb4 61. Qd8+ Kg7
>>>62. Qd4+ 1-0
>>>
>>>Position after move 61. Kg7:
>>>
>>>[D]3Q4/6k1/p5p1/6P1/Pq6/4P1K1/8/8 w - -
>>>
>>>After 62. Qf6+ is the win not easy. But after 62. Qd4+ is the game easy to win,
>>>and the game end! For any programs ist the move Qd4+ not easy to find.
>>>
>>>:-(
>>>
>>>S532 finds the move with TBs after 58 seconds on P600:
>>>
>>>Analysis by Shredder 5.32:
>>>
>>>
>>>1.Df6+ Kh7 2.Dxa6 De1+ 3.Kg4 Dg1+ 4.Kf4 Dh2+ 5.Ke4 Dg2+ 6.Kd4 Dxg5 7.Db7+ Kh8
>>>  +-  (2.33)   Tiefe: 11/22   00:00:44  7096kN, tb=6535
>>>1.Dd7+ Kg8 2.De6+ Kh7 3.Dxa6 De1+ 4.Kg4 Dg1+ 5.Kf4 Dh2+ 6.Ke4 Dg2+ 7.Kd4 Dxg5
>>>8.Db7+ Kh8
>>>  +-  (2.34)   Tiefe: 11/22   00:00:46  7474kN, tb=6990
>>>1.Dd7+ Kg8 2.De6+ Kh7 3.Dxa6 De1+ 4.Kg4 Dg1+ 5.Kf4 Dh2+ 6.Ke4 Dg2+ 7.Kd4 Dxg5
>>>8.Db7+ Kh8
>>>  +-  (2.34)   Tiefe: 11/22   00:00:52  8440kN, tb=7665
>>>1.Dd4+ Dxd4 2.exd4 Kf7 3.Kf4 Ke6 4.Ke4 Kf7
>>>  +-  (2.35)   Tiefe: 11/22   00:00:58  9490kN, tb=8444
>>>1.Dd4+ Dxd4 2.exd4 Kf7 3.Kf4 Ke6 4.Ke4 a5 5.d5+ Kd7 6.Ke5 Ke7 7.d6+
>>>  +-  (2.66)   Tiefe: 11/22   00:00:58  9494kN, tb=8444
>>>
>>>
>>>For Tiger 14 is this not so easy:
>>>
>>>Analysis by Chess Tiger 14.0:
>>>
>>>1.Df6+ Kh7 2.Dxa6 De1+ 3.Kg2 Dxe3 4.Db7+ Kg8 5.Dc8+ Kf7 6.Dd7+ Kg8 7.Dd5+ Kg7
>>>8.a5 De2+ 9.Kg3 De1+
>>>  +-  (2.28)   Tiefe: 15   00:03:00  37784kN, tb=595
>>>1.Dd4+ Dxd4 2.exd4 Kf7 3.d5 Ke7 4.Kf4 Kd6 5.Ke4 a5 6.Kd4 Ke7 7.Ke5 Kf7 8.d6 Ke8
>>>9.Kf6
>>>  +-  (2.36)   Tiefe: 15   00:03:31  44143kN, tb=712
>>>1.Dd4+
>>>  +-  (3.26)   Tiefe: 16   00:03:52  48366kN, tb=955
>>>
>>>Eduard
>>
>>
>>This is more about specific knowledge than speed.  On a 600mhz laptop, I get
>>this:
>>
>>         (2)   11    12.57   1.86   1. Qf6+ Kh7 2. Qxa6 Qe1+ 3. Kg2 Qxe3
>>                                    4. Qb7+ Kh8 5. Qb8+ Kg7 6. Qc7+ Kg8
>>                                    7. Qc8+ Kf7 8. Qd7+ Kg8 9. Qd5+ Kg7
>>                                    10. a5
>>               11    19.60   1.99   1. Qd4+ Qxd4 2. exd4 Kf7 3. d5 Ke7
>>                                    4. Kf4 Kd6 5. Ke4 a5 6. Kd4 Kd7 7.
>>                                    Ke5
>>         (4)   11->  19.62   1.99   1. Qd4+ Qxd4 2. exd4 Kf7 3. d5 Ke7
>>                                    4. Kf4 Kd6 5. Ke4 a5 6. Kd4 Kd7 7.
>>                                    Ke5
>>         (3)   12    19.64   2.05   1. Qd4+ Qxd4 2. exd4 Kf7 3. Kf4 Ke6
>>                                    4. Ke4 Kd6 5. a5 Ke6 6. d5+ Kd6 7.
>>                                    Kd4 Kd7 8. Ke5
>>
>>
>>etc...
>
>It may be about search rules and not only about evaluation.
>
>I know that programs have often problem in the transition to pawn endgames.
>
>If you give them the position after 1.Qd4+ Qxd4 2.exd4 they are going to see
>that white wins with no problem but if you give them the root position they are
>going to see nothing and the reason is simply bad search rules.
>
>If the remaining depth after 1.Qd4+ Qxd4 2.exd4 is x plies by normal rules then
>it should be bigger than x for example x*3/2 because the position after 2.exd4
>is the starting position of a pawn endgame.

I do something similar in Gaviota. I extend in the transition to
a pawn endgame. This is something that can be tuned, though.
Despite that Gaviota has NO knowledge of pawn endgames (yet) it finds Qd4+ in
160 s in a PIII 700 mhz. Not great at all, but not so bad compared to the
commercials posted here.
Anyway, 160 s is a shame. Any human would play that in a fraction of a second
and later think.

Regards,
Miguel

>
>I do not know if 3/2 is the best number and it is possible to try other
>functions of x but basically they should search pawn endgame deeper because the
>time that they need to get the same depth is smaller.
>
>Uri



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