Author: José de Jesús García Ruvalcaba
Date: 09:31:11 11/20/99
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On November 20, 1999 at 10:24:46, Robert Hyatt wrote: [big snip] > >This can cause serious problems. There is a well-documented search/evaluation >problem called "the discontinuity problem". If you suddenly switch from one >engine to another, then at positions around this 'switch' you can make gross >errors. Or you do like Fritz and have an eval of +1 before trading queens, >and 0.00 after trading. The evaluation/search has to perform in a continuous >way, slowly transitioning from opening to middlegame, and from middlegame to >endgame. I used to have three distinct 'phases'. I am slowly eliminating >those and making the program perform better. > >I don't believe it will be possible to beat GM players consistently with big >discontinuities in the evaluation, or in the search space. They will notice >the 'transition points' and take advantage of this. In ways detrimental to >the program. It has happened to me many times. > >An example is king safety. You want to slowly phase it out as you approach >the endgame, not just <wham> it is off. Because you might reach a position >where your king shelter is gone, and you give up a pawn to trade away the >piece that drops the king safety term to zero. And convert a likely win into >a sure draw/loss. > >IE "think smooth" not "jerky"... Hi Bob, strictly speaking, the evaluation function is always continous, as its domain is a discrete space. Of course I understand what you mean, wanting a "more continous" evaluation function, i.e., one with less variation. José.
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