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Subject: Re: Interesting mate test for hashing

Author: Robert Hyatt

Date: 06:49:02 09/10/99

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On September 10, 1999 at 07:49:10, Steffen Jakob wrote:

>Hi Werner!
>
>On September 10, 1999 at 04:35:00, Inmann Werner wrote:
>
>>Hello Steffen :)
>>
>>A real "nice" position. Inmichess seems as dumb as....
>
>dumb but fast! :-)
>
>>First a Mate in 7, then on blacks move, it gets right.
>>Needs also 13 plys to find a mate.
>
>At the moment Hossa needs 11 plies to see a mate in 7 (49442 nodes) and 13 plies
>to get the mate in 6 (615443 nodes). If you consider that Hossa ran into an
>endless loop until yesterday when he reached ply 11 then this is a serious
>improvement ;-)
>
>My goal is to see immediately (== 1 node) that black can force the pawn
>promotion. I think this can be done if Hossa recognize that white pawns in the
>pawn clusters a6/a7 and g6/h5/h4 are useless. Then you can forget all those
>pawns and only look at the position Kg3,Ke4,f3 where it is easy to see that
>black can _soon_ get a queen. Of course this needs a lot of work.
>
>>Also Inmichess loves G3-H2, you know my ugly endgame evaluation :(
>>
>>Will try it with 2.18 in the evening, maybe my new extensions help a little to
>>find earlier?
>
>I haven't done any work on that but we better discuss this via Email (or better:
>personally in Mondsee soon again :-)
>
>>As we said, hashing is a complicate thing......
>
>>greetings to Vienna
>
>Viele Gruesse nach Mondsee,
>Steffen.

I do a lot of this directly in eval.  The passed pawn is supported by the
king (big bonus).  In Cray Blitz (not sure about crafty but will certainly
look) it realizes that the pawn queens, because the queening square is
attacked by the king with no enemy pieces except the king defending the
square...

but you are right, you want to categorize this is 'probably winning' at least,
so that you can search up to this position and recognize it, rather than having
to search thru this position and hope you get to a won position before you are
out of depth...



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