Author: Angrim
Date: 19:57:37 09/06/01
Go up one level in this thread
On September 06, 2001 at 17:07:59, Dieter Buerssner wrote:
>On September 06, 2001 at 14:36:18, Peter Berger wrote:
>
>>5n2/B3K3/2p2Np1/4k3/7P/3bN1P1/2Prn1P1/1q6 w - - 0 1
>>
>>It is supposed to be a mate in 30 (source unknown to me).
>>
>>Bringer (http://www.reubold.onlinehome.de) announces a mate in 29 after about
>>one minute :
>>
>>0:00:33.6 (11/59) 13872159 5.61 e3-g4 e5-f5 g4-h6 f5-e5 h6-f7 e5-f5
>>f7-d6 f5-e5 f6-g4 e5-d5 c2-c4
>>0:01:16.8 (12/59) 32704069 Matt in 29 e3-g4 (Mat=-1320,50=1)
>>0:01:45.0 (12/59) 49458897 Matt in 29 e3-g4 e5-f5 (Mat=-1320,50=2)
>>
>>What do others think ?
>
>Well, Yace cannot compete here. With some help, it finds a mate in 30 (after 4
>moves, it could see the mate). Here is the line:
>
> 12241895 43.425 Mat30 10. 1.Neg4+ Kf5 2.Nh6+ Ke5 3.Nf7+ Kf5 4.Nd6+ Ke5
> 5.Ng4+ Kd5 6.Ne3+ Ke5 7.Nf7+ Ke4 8.Ng5+ Ke5
> 9.Nf3+ Ke4 10.Nxd2+ Ke5 11.Nf3+ Ke4 12.Ng5+ Ke5
> 13.Nf7+ Ke4 14.Nd6+ Ke5 15.Ng4+ Kd5 16.Nf6+ Ke5
> 17.Nf7+ Kf5 18.Nh6+ Ke5 19.Nhg4+ Kf5 20.Ne3+
> Ke5 21.Nfg4+ Ke4 22.Nf2+ Ke5 23.Nxd3+ Ke4
> 24.Nf2+ Ke5 25.Nfg4+ Ke4 26.Nf6+ Ke5 27.Nc4+
> Kf5 28.Nd6+ Ke5 29.Ng4+ Kd5 30.c4# {-491}
>
>I think, a program that aggressively extends all forced moves could be fast
>finding this.
Well, thats just about the definition of proof number search :) so I
tried it, and you are correct.
useing pn^2 search on an athlon 1.2ghz:
proved that move e3g4 wins, 29 turns
PN2:960772 evals, 84951 expands, 3.81 seconds
Angrim
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