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Subject: Re: How long does it take to your engine to find this move?

Author: Jaime Benito de Valle Ruiz

Date: 17:46:38 10/07/03

Go up one level in this thread


On October 07, 2003 at 20:35:29, Slater Wold wrote:

>On October 07, 2003 at 19:18:34, Jaime Benito de Valle Ruiz wrote:
>
>>[d]3r1r2/pb3pkp/1pn2Np1/2p1PP2/8/b2BQ3/qP4PP/3R1R1K w - - 0 3
>>
>>1.Nh5+ is a winning move, but the really smashing one is 1.Nxh7!
>
>I cannot find an engine that does not select Nh5+ right off the bat.  Granted,
>most have either negative or draw scores, that creep up slightly after time
>passes.  Crafty 19.4, Tao, SmarThink, etc., etc.
>
>Nxh7 however is "extension heavy" I believe.  All engines pause and seem to take
>a deep look at it, but most don't choose it.
>
>However, Ruffian does something interesting.  It finds Nh5+, likes it, finds a
>draw score with it, fails high on it, evens out at +1.25, then it fails low on
>Nh5+ with a draw score, takes a deep look at Nxh7 and chooses it.  Weird!
>
>
>Ruffian 1.0.5
>3r1r2/pb3pkp/1pn2Np1/2p1PP2/8/b2BQ3/qP4PP/3R1R1K w - - 0 1
>
>Analysis by Ruffian 1.0.5:
>
>1.bxa3 Qxa3 2.fxg6 hxg6
>  µ  (-0.98)   Depth: 1/4   00:00:00
>1.bxa3 Qxa3 2.fxg6 hxg6
>  µ  (-0.98)   Depth: 2/8   00:00:00
>1.bxa3 Nxe5 2.Nh5+ Kg8 3.Qxe5 gxh5
>  -+  (-1.57)   Depth: 3/10   00:00:00
>1.bxa3 Nxe5 2.Nh5+ gxh5 3.Qxe5+ Kh6
>  -+  (-1.59)   Depth: 4/11   00:00:00
>1.bxa3 Nxe5 2.Nh5+ gxh5 3.Qxe5+ Kg8 4.Qg3+ Kh8 5.Qe5+ Kg8
>  -+  (-1.57)   Depth: 5/16   00:00:00
>1.bxa3 Nxe5 2.Nh5+ Kg8 3.Nf6+ Kh8 4.Be4 Bxe4 5.Qxe4
>  -+  (-2.20)   Depth: 6/17   00:00:00  160kN
>1.fxg6 fxg6 2.bxa3 Nxe5 3.Nh5+ Kg8 4.Rxf8+ Rxf8 5.Qxe5 gxh5 6.Be2
>  -+  (-1.76)   Depth: 6/19   00:00:00  545kN
>1.fxg6 fxg6 2.bxa3 Nxe5 3.Be4 Rxf6 4.Bxb7 Rxd1 5.Rxd1
>  -+  (-2.37)   Depth: 7/21   00:00:01  1363kN
>1.bxa3 Nxe5 2.Nh5+ Kg8 3.Nf6+ Kh8 4.Be2 Nc4 5.Qe7
>  -+  (-2.17)   Depth: 7/21   00:00:01  1608kN
>1.Nh5+
>  -+  (-1.41)   Depth: 7/23   00:00:02  2469kN
>1.Nh5+ Kh8 2.Qh6 Rg8 3.fxg6 fxg6 4.Nf6 Rg7 5.bxa3 Nxe5
>  µ  (-1.09)   Depth: 7/23   00:00:02  2516kN
>1.Nh5+ Kh8 2.Qh6 Rg8 3.fxg6 fxg6 4.Bxg6 Rxg6 5.Rxd8+ Nxd8 6.Rf8+ Qg8 7.Rxg8+
>Kxg8 8.Nf6+ Rxf6 9.Qxf6
>  µ  (-0.81)   Depth: 8/23   00:00:02  2924kN
>1.Nh5+
>  ³  (-0.46)   Depth: 9/27   00:00:06  6586kN
>1.Nh5+ Kh8 2.Qh6 Rg8 3.fxg6 fxg6 4.Bxg6 Rxg6 5.Rxd8+ Nxd8 6.Rf8+ Qg8 7.Rxg8+
>Kxg8 8.Nf6+ Rxf6 9.Qxf6 Bxb2 10.Qxd8+
>  =  (-0.18)   Depth: 9/27   00:00:06  7195kN
>1.Nh5+
>  =  (0.17)   Depth: 10/31   00:00:10  12039kN
>1.Nh5+ Kh8 2.Qh6 Rg8 3.fxg6 fxg6 4.Bxg6 Rxg6 5.Rxd8+ Nxd8 6.Rf8+ Qg8 7.Rxg8+
>Kxg8 8.Nf6+ Rxf6 9.exf6 Bxg2+ 10.Kxg2 Bxb2
>  ²  (0.45)   Depth: 10/31   00:00:11  13165kN
>1.Nh5+
>  ±  (0.80)   Depth: 11/31   00:00:18  21319kN
>1.Nh5+ Kh8 2.Qh6 Rg8 3.fxg6 fxg6 4.Bxg6 Rxg6 5.Rxd8+ Nxd8 6.Rf8+ Qg8 7.Rxg8+
>Kxg8 8.Nf6+ Kf7 9.Qxh7+ Ke6 10.bxa3 Rxg2
>  +-  (1.60)   Depth: 11/31   00:00:22  26525kN
>1.Nh5+
>  ±  (1.25)   Depth: 12/35   00:01:18  98714kN
>1.Nh5+ Kh8 2.Qh6 Rg8 3.fxg6 fxg6 4.Bxg6 Rxg6 5.Rxd8+ Nxd8 6.Rf8+ Qg8 7.Rxg8+
>Kxg8 8.Nf6+ Kf7 9.Qxh7+ Rg7 10.Qh5+ Rg6 11.Qh7+
>  =  (0.00)   Depth: 12/35   00:01:36  121585kN
>1.Nxh7 Rxd3 2.Rxd3 Kxh7 3.fxg6+ fxg6 4.Qh3+ Kg8 5.Rxf8+ Kxf8 6.Qh8+ Ke7 7.Qg7+
>Qf7 8.Rd7+ Kxd7 9.Qxf7+ Ne7 10.bxa3 Bd5 11.Qf4
>  +-  (1.44)   Depth: 12/35   00:05:54  417987kN

This is what I found interesting about this position: How the score changes so
much all of a sudden in certain positions, and how some "apparently" harmless
position could cause so much damage!



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