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Subject: Re: To Bob Hyatt:crafty KRP vs KR special code (repetition of my questio

Author: Robert Hyatt

Date: 08:45:02 02/08/04

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On February 08, 2004 at 05:44:15, Uri Blass wrote:

>I guess that you missed my previous post about it when I asked where is that
>code in crafty
>
>http://www.talkchess.com/forums/1/message.html?347698
>
>Uri


Yes, sorry.  For some unknown reason, I don't see _every_ post, unless there is
a follow-up.  No idea why.  In any case, I had to look back thru my summary of
changes, and I found the following...

I wrote some special code for krp vs kr, and it worked pretty well.  The idea
was to use the rook to keep the opposing king as far away as possible, bring the
king up with the pawn with the rook ready to help with checks from the rear.
However, I then found the usual exceptions, and now all I do is have code to
understand that the king needs to be as close to the passed pawn(s) as possible,
both sides.  This is enough so that Crafty will use its rook to keep your king
away, while it advances the pawn to the point where the search can see the win
(if it is winnable).  I chose to do it this way as I needed that "concept"
anyway in order to play reasonable endgames, and once that idea was built in to
Crafty, the other code was not needed and was removed in a clean-up cycle...

I simply want both kings to try to control the queening square of the pawn(s)
and that's enough, if you don't screw up with the rook on the 7th stuff.  IE if
your king is at a8, my pawn is on the f-file, I want my rook on the b-file.
When you attack it with your king, I do _not_ want to keep it on the 7th since
there are no pawns to attack on the 7th, instead I want to keep it on the b-file
to keep your king out of play.  That is really enough to win most that are
winnable and draw most that are drawable, without adding much code at all...

I do have special-case code for kp vs k, still...



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