Author: Robert Hyatt
Date: 07:23:58 07/29/99
Go up one level in this thread
On July 29, 1999 at 09:46:58, Chris Carson wrote: >On July 29, 1999 at 09:29:32, Robert Hyatt wrote: > >>On July 29, 1999 at 08:25:58, Chris Carson wrote: >> >>>On July 29, 1999 at 07:16:32, Amir Ban wrote: >>> >>>>On July 28, 1999 at 18:16:24, Dann Corbit wrote: >>>> >>>>>On July 28, 1999 at 17:50:51, Kristo Miettinen wrote: >>>>> >>>>>>The position is the opening array, all pieces in their initial positions. The >>>>>>explanation about the eight pawns makes sense, intending to steer Crafty into >>>>>>open waters (on the assumption that the opponent is human?) >>>>>> >>>>>>I was looking into this on a whim, as I use the advantage of White in the >>>>>>opening position as my quantum of positional value (on which scale the value of >>>>>>a pawn is 6 quanta for me). >>>>>Here is the C.A.P. record for that position. >>>>> >>>>>rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - acd 15; ce -7; pv e4 e6 Nf3 >>>>>Bb4 Nc3 Ne7 Bc4 Nbc6 O-O O-O d4 Bxc3 bxc3 Na5 Bb5; pm e4; id "C.A.P. 4028"; >>>>> >>>>>I bet you never knew crafty was French. >>>>> >>>>>Crafty thinks it is behind by 7 one hundredths of a pawn. This is obviously >>>>>conservative because white has a tempo at least. But I don't think that it is >>>>>grossly inaccurate. >>>> >>>>A correct evaluation is one that matches the winning percentages of the >>>>position. I think white has about 54% in serious play, and if so the evaluation >>>>should be about +0.20. >>>> >>>>Amir >>> >>>Amir, >>> >>>Interesting point. If I read you correctly, the "Evaluation" should match >>>the winning changes. This is not the way most programs "Evaluate" a position. >>>Granted that a higher "Eval" by a program should mean a higher "Chance" to >>>win, it is normally not a "Percentage" based on results. >>> >>>I have thought that this might be a better method of "Evaluation", some >>>programs do use a "Percentage" (Crafty) for opening book moves, but not >>>for middle game or end game positions. >>> >>>Any thoughts on how to incorporate "Percentage" into the "Evaluate" function >>>of a program (knowledge)? Perhaps a "Percentage" "Evaluation" for positions >>>and endgames as a part of the learning (Crafty might be able to do this) >>>would be useful. Any comments? >>> >>>Best Regards, >>>Chris Carson >> >> >>I disagree. Evaluations are not 'absolute' any more than FIDE Elo ratings are >>absolute. The correct evaluation is the one that lets you _win_ 54% (or better) >>of the games from the opening position. Whether the starting score is +1.00 or >>-1.00 is immaterial so long as you choose the best move(s) by using those >>scores... > >I agree with you, this makes the evaluation relative to the program/version >that is doing the evaluation, thus a +0.3 may have a different meaning >for program x than for program y, but is irrelevant as long as the >best move is choosen by the program using the score. > >Best Regards, >Chris Carson right.. ie a good eval could produce -1, 0 and 1 and play using those scores just so they are right. That program could also use -1001, -1000, and -999 and produce the same result...
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