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Subject: Re: Behting position

Author: Enrique Irazoqui

Date: 06:09:45 09/03/98

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On September 02, 1998 at 16:21:15, Bruce Moreland wrote:

>
>On September 01, 1998 at 15:57:49, Djordje Vidanovic wrote:
>
>>Bernhard Bauer claims that this kind of position NEVER occurs in real games...
>>But it does -- therefore I AM taking his claim *cum grano salis* :-)
>>Anyway, here goes:
>>
>>>[FEN "8/8/8/5pp1/8/1K6/2pp1Q2/2k5 w - - 0 1"]
>>>[PlyCount "5"]
>>>[EventDate "1907.??.??"]
>>
>>1. Qe3 f4 2. Qf2 d1=Q (2... f3 3. Qe3) 3. Kc3 f3 4. Qe3+ Kb1 5. Qb6+ Kc1 6. Qb2#
>>1-0
>>
>>This is a relatively simple position where white wins in 12 plies or less, but
>>several programs fail to find Qe3, even after a search deeper than 12 plies.
>>
>>After at least 5 minutes on a PII-400 with 256 MB RAM, Hiarcs 6, Fritz 5, Mchess
>>7.1, Nimzo 98, Crafty 15.17, Exchess 2.34 and Junior 4.6 don’t find the
>>solution. Junior plays instantaneously Kc3?? and announces mate in 4,
>>overlooking the obvious underpromotion d1N+.
>>
>>Time to find Qe3 with a winning evaluation:
>>Genius 5W, 13 secs.
>>Rebel 9, 30 secs.
>>Rebel 10, 24 secs.
>>Shredder 2, 24 secs.
>>
>>>Strange that there is so much difference between programs in this position.
>>
>>>What would Ferret, Dark Thought and others play?
>
>Mine doesn't find this.  I sacrifice some of the freakish cases.

This is not such a freakish case. There are hundreds of games with King+Queen
vs. King+pawns. An example among many:

Benko-Byrne, 1958
7K/3P1P2/8/7P/8/8/5P2/kq6 b - - 0 62

>My thinking is
>that I would rather miss a few wins than find all of the losses.

In this case you got a 50% success... :)

>Hopefully I am not also sacrificing the non-freakish cases.
>
>Genius seems to have some stuff in it that lets it find some null-move killer
>positions quickly.  I'm surprised that Shredder finds it.  I don't know about
>Rebel.

But this was my point when I posted this position. Genius, Rebel, Shredder, CM5K
and others find quickly the right move, and don't tell me they are not
nullmovers. But maybe more accurate nullmovers than others?

Enrique

>bruce



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