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Subject: Re: another solution for WAC96

Author: Uri Blass

Date: 08:40:54 01/02/02

Go up one level in this thread


On January 02, 2002 at 11:26:06, Robert Hyatt wrote:

>On January 02, 2002 at 11:19:52, Uri Blass wrote:
>
>>[D]r1b4k/ppp2Bb1/6Pp/3pP3/1qnP1p1Q/8/PPP3P1/1K1R3R w - - bm Qd8+;
>>
>>It is WAC96
>>
>>Qd8+ is a forced mate for white but b3 is also enough to win the game.
>>
>>I saw cases when stupid moves are considered as solutions for WAC only because
>>they are winning so in this case b3 should be considered as an alternative
>>solution:
>>
>>after b3 I gave yace to learn that Na3+ Kc1 is bad for black and it give the
>>folllowing analysis:
>>New position
>>r1b4k/ppp2Bb1/6Pp/3pP3/1qnP1p1Q/1P6/P1P3P1/1K1R3R b - - 0 1
>>
>>Analysis by Yace 0.99.56:
>>
>>1...Qxb3+ 2.axb3
>>  +-  (9.15)   Depth: 1   00:00:00
>>1...Nxe5 2.dxe5
>>  +-  (2.61)   Depth: 1   00:00:00
>>1...f3 2.gxf3
>>  +-  (1.57)   Depth: 1   00:00:00
>>1...Rb8 2.Bxd5
>>  ±  (1.34)   Depth: 1   00:00:00
>>1...Bf5 2.Bxd5
>>  ±  (1.12)   Depth: 1   00:00:00
>>1...c6 2.Qxf4
>>  ±  (1.04)   Depth: 1   00:00:00
>>1...Ne3
>>  ²  (0.26)   Depth: 1   00:00:00
>>1...Ne3 2.Qd8+ Qf8
>>  ²  (0.48)   Depth: 2   00:00:00
>>1...Ne3 2.Qd8+ Qf8 3.Qxf8+ Bxf8 4.Rdg1
>>  =  (0.07)   Depth: 3   00:00:00
>>1...Ne3 2.Qxf4 Bxe5 3.Rxh6+ Kg7 4.Qxe5+ Kf8
>>  ²  (0.47)   Depth: 4   00:00:00
>>1...Ne3 2.Qxf4 Nf5 3.Bxd5
>>  +-  (2.27)   Depth: 4   00:00:00
>>1...Bf5 2.Bxd5 Bxc2+ 3.Kc1
>>  +-  (2.26)   Depth: 4   00:00:00
>>1...Bf5 2.Qxf4 Bd7 3.Bxd5
>>  +-  (1.91)   Depth: 4   00:00:00
>>1...f3 2.Qd8+ Qf8 3.Qxf8+ Bxf8 4.bxc4 fxg2 5.Rdf1
>>  +-  (1.90)   Depth: 4   00:00:00
>>1...f3 2.Qd8+ Qf8 3.Qxf8+ Bxf8 4.bxc4 fxg2 5.Rhg1
>>  +-  (1.83)   Depth: 4   00:00:00
>>1...Nb6 2.Qd8+ Qf8 3.Rde1
>>  +-  (1.82)   Depth: 4   00:00:00
>>1...Nb6 2.Qxf4 Qf8 3.Rdf1
>>  +-  (1.76)   Depth: 4   00:00:00
>>1...Nb6 2.Qd8+ Qf8 3.Qxc7 Bg4 4.Rdf1
>>  +-  (1.62)   Depth: 5   00:00:00  49kN
>>1...Nb6 2.Qd8+ Qf8 3.Qxc7 Bg4 4.Rdf1 Qc8 5.Qxc8+ Rxc8 6.Rxf4
>>  +-  (1.82)   Depth: 6   00:00:00  129kN
>>1...Qf8 2.Kc1 Bf5 3.Qg5 Qa3+ 4.Kb1
>>  +-  (1.81)   Depth: 6   00:00:00  129kN
>>1...Qf8 2.Qxf4 Na3+ 3.Kc1 c6 4.Rdf1 Bd7
>>  +-  (1.41)   Depth: 6   00:00:00  129kN
>>1...Qf8 2.e6 Na3+ 3.Kc1 c6 4.e7 Bf5 5.exf8Q+ Bxf8
>>  +-  (1.81)   Depth: 7   00:00:01  402kN
>>1...Qf8 2.e6 Bxe6 3.Bxe6 Qa3 4.Qf6 Bxf6 5.bxc4
>>  +-  (1.81)   Depth: 7   00:00:01  402kN
>>1...Qf8 2.Qxf4 Na3+ 3.Kc1 b6 4.Rxh6+ Bxh6 5.Bxd5
>>  +-  (1.49)   Depth: 8   00:00:03  1176kN
>>1...Qf8 2.Qxf4 Na3+ 3.Kb2 Bd7 4.Rxh6+ Bxh6 5.Rh1 Qxf7 6.gxf7 Kg7 7.f8Q+ Rxf8
>>8.Qxh6+ Kf7
>>  +-  (1.89)   Depth: 9   00:00:07  2235kN
>>1...Qf8 2.Qg5 Ne3 3.Rxh6+ Bxh6 4.Rh1 Ng4 5.e6 Bxe6 6.Bxe6 f3 7.Qxg4
>>  +-  (2.33)   Depth: 9   00:00:11  4029kN
>>1...Qf8 2.Qg5 Ne3 3.Rxh6+ Bxh6 4.Qf6+ Qg7 5.Rh1 Bh3 6.Rxh3 Ng4 7.Qxf4 Qxf7
>>8.gxf7 Nxe5
>>  +-  (2.73)   Depth: 10   00:00:26  9166kN
>>1...Qf8 2.Qxf4 Bf5 3.Qxf5 Ne3 4.Rxh6+ Bxh6 5.Qf6+ Qg7 6.Rh1 Ng4 7.Qf4 c6 8.Qxg4
>>Rf8
>>  +-  (4.05)   Depth: 10   00:00:44  15973kN
>>1...Qf8 2.Qxf4 Bf5 3.Qxf5 Ne3 4.Rxh6+ Bxh6 5.Qf6+ Qg7 6.Rh1 Ng4 7.Qf4 c6 8.g3
>>Rf8 9.Qxg4
>>  +-  (4.14)   Depth: 11   00:01:53  41818kN
>>1...Qf8 2.Qxf4 Bf5 3.Qxf5 Ne3 4.Rxh6+ Bxh6 5.Qf6+ Qg7 6.Rh1 Ng4 7.Qf4 c6 8.Qxg4
>>Qxf7 9.gxf7 Kh7
>>  +-  (4.54)   Depth: 12   00:03:42  79943kN
>>1...Qf8 2.Qxf4 Bf5 3.Qxf5 Ne3 4.Rxh6+ Bxh6 5.Qf6+ Qg7 6.Rh1 Ng4 7.Qf4
>>  +-  (4.54)   Depth: 12   00:04:00  87418kN
>>1...Qf8 2.Qxf4 Bf5 3.Qg5 Na3+ 4.Kb2 Nxc2 5.Rxh6+ Bxh6 6.Qf6+ Qg7 7.Rh1 Bxg6
>>8.Be8
>>  +-  (4.54)   Depth: 13   00:11:00  218149kN
>>
>>(Blass, Tel-aviv 02.01.2002)
>>
>>
>>Uri
>
>
>If b3 isn't a forced mate, then I disagree.  WAC is about finding the best
>move in a position.  If several moves lead to the same score, then they are
>all reasonable solutions. But if one leads to +4 and one leads to a forced
>mate, the +4 is wrong, because the program simply isn't seeing deep enough
>to see the _real_ issue...

programs can also play Qd8+ for the wrong reason so by this logic
program that found Qd8+ without the right score also did not solve it.

Here is another example from WAC
Wac31
[D]rb3qk1/pQ3ppp/4p3/3P4/8/1P3N2/1P3PPP/3R2K1 w - - bm Qxa8 d6 dxe6 g3

A program that plays Qxa8 at depth 1 does not see the real reason that it is
winning but Qxa8 is considered as a solution in Dann corbit's site.



Uri



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