Author: Robert Hyatt
Date: 07:26:57 08/31/99
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On August 31, 1999 at 04:51:18, Ricardo Gibert wrote: >On August 31, 1999 at 00:30:24, Howard Exner wrote: > >>On August 30, 1999 at 19:41:54, Ralf Elvsén wrote: >> >>>Some while ago I posted a position where I was >>>impressed by Hiarcs accurate evaluation in a pawn ending: >>> >>>6k1/1p4p1/p7/2Ppp3/1P6/P4KP1/5P1P/8 b - - 0 49 >>> >>>The fact that white can create passed pawns on >>>both sides of the board makes the victory clear, >>>and Hiarcs gave an evaluation of about +2. Note however >>>that white is a pawn up. >>> >>>Not being entirely convinced about the >>>impeccabilty of its evaluation, I decided to test >>>some similar "clean" positions. >>> >>>First position: >>> >>>4k3/p6p/8/4p3/3p4/3K4/PP4PP/8 b - - 0 1 >>> >>>This is (from a human point of view) an "identical" position but >>>with material equality. A win for white. Here Hiarcs thinks black >>>is slightly better! >>> >>>Second position: >>> >>>4k3/p6p/8/3p4/2p5/2K5/P4PPP/8 b - - 0 1 >>> >>>Here one pawn is moved from one side of the board to the other >>>(compared to the previous position) and that makes it a clear draw, >>>but Hiarcs thinks white has an advantage, although not decisive. >>>So Hiarcs thinks position 2 is better for white than position 1, >>>when in fact it is worse. >>> >>>I am now inclined to believe (or rather convinced...) >>>that Hiarcs correct score in the position from my >>>original post was due to the fact that white was a pawn up in a pawn ending, >>>(which is heavily weighted, understandably) and not from some accurate >>>evaluation of the pawn structure... >>> >>>Don't investigate the chess "knowledge" of your favourite chess software, >>>your illusions can be shattered :) >>> >>>Ralf >>> >>>PS: I always screw things up when I post positions and other stuff. >>>Hope I got it right this time... >> >>6k1/1p4p1/p7/2Ppp3/1P6/P4KP1/7P/8 b >> >>Here is your original position minus the white pawn on f2, >>so now material is equal. Like Hiarcs' eval of the original >>Rebel 10 also gives a big plus for white. But now in this equal material >>position which remains a very simple win for white, Rebel 10 thinks black is >>much better. It seems that only deep calculation will aid computers here >>while humans see this at a glance. > >Yes. Computers cannot calculate far enough to "understand" these positions. >Their evals are not much better than "random noise". They can do tactics & in >many respects positional play, but stategy (i.e. planning) is neglected, which >is what is needed here. To do stategy, they need to be able to generalize and >they don't do that. If you hold that thought for a few months, and try this on crafty, it will work... recognizing outside passed pawns has been in crafty for years now, as it was in Cray Blitz... and it understands that outside passed pawns get more valuable as pieces come off the board. Recognizing a pawn majority is no more difficult and will solve a bunch of similar positions...
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