Author: Claudio A. Amorim
Date: 06:55:43 09/17/99
Go up one level in this thread
On September 16, 1999 at 23:59:25, Robert Hyatt wrote: >First, a little background. I have been doing 'outside passed pawn' scoring >for years now, because I got tired of seeing Crafty lose endings where it was >a pawn up, and it traded down to the point where it was a king and pawns vs >king and pawns ending, where the opponent had an outside passed pawn that made >it an easy win... > >OK... that was fairly easy to code using bitmaps... and it has worked well. >But once you get past that hurdle, you begin to see endings where you trade >down to a pawn-up ending, but your opponent has a queen-side majority that >turns into an outside passer outside the search horizon, and the same issue >comes up again. > >I am working on addressing this now, and am looking for a discussion on what >might be the best way to do this. > >I have completed a fairly accurate 'candidate passed pawn' analyzer. It is >in the EvaluatePawns() code so that it is all hashable and won't cost a fortune. > >All it does is simply look at each pawn that has no enemy pawn in front of it, >and decides whether pushing that pawn can make a passer or not. Again, not >hard using bitmaps, and in studying the results, it looks reasonable. My intent >is to use this in the absense of any outside passed pawns for one side, to see >if it has any potential outside passed pawns on that side of the board. And >for the usual 3 vs 2 queen-side majorities, it works cleanly and accurately. > >But what about 4 vs 3? Where the passer ends up on the d-file, which might >not be far enough away to cause problems. Or what about 3 vs 3, where one >side has pawns on a-b-c, the other side has pawns on b-c-d, and both end up >with a passer although the abc passer will be more distant. > >I guess my question is, has anyone given any thought to this? Or is anybody >even dealing with pawn majorities at present? I tend to not actually call this >majority code any longer, because it is _really_ candidate passed pawn >evaluation instead... > >My intention is to recognize that if the kings are on g1/g8, and white has >the a-b-c pawns and black just has b-c pawns, that this is a nearly winning >position. I am going to do just like I do with outside passers, that is, have >their value go up as material goes down, as they don't mean much with queens and >pieces on the board... > >Any comments, suggestions, ideas, etc? > >Obviously necessary, yet I don't see any evidence that any program does much >with this excepting for deep blue... > >Bob Plain brute force is the answer. Given a sufficiently powerful hardware and a search algorithm good enough, the problem shall be over (as any other positional-judgement problem, for that matter)... Or not?
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