Author: Vincent Diepeveen
Date: 11:31:16 10/04/02
Go up one level in this thread
On October 04, 2002 at 12:28:54, Sune Fischer wrote: >On October 04, 2002 at 12:14:18, Omid David wrote: >>>>Wrong. I've conducted hundreds of tests, and in no single case has my heuristic >>>>returned an inaccurate result. There exist blockades that it fails to detect, >>>>but it never declares a false draw. >>> >>>Perhaps this is too restrictive too. >>>You could have some confidence variable, if you draw detector cannot say with >>>100% certainty that it's draw, then interpolate the evaluated score with the >>>confidence level: score=eval()*(100-confidence)/100. >>> >>>It might help the engine to steer clear of those drawish positions? >> >>But as Vincent pointed out, such heuristics have an overriding nature. Even the >>slightest inaccuracies can result in a total disaster. > >Yes I know, you have to be careful, right now I don't even score KRKR as draw, >because what if the one to move can give a check and take the other rook hiding >behind the king... > >If there is a high probability of a draw, eg. a risk of perpetual check because >your king is exposed and his queen is near by, then be less optimistic in your >score even if you are way ahead in material. It is probably easier to win >without the queens on the board if you have an extra knight, for instance. At >least you have eliminated the risk of perpetual check. One of the things we are talking about here is that black is a pawn down. Not about KR KR or something. KR KR is not a 'blocked position'. He talks about recognizing something as blocked and therefore giving a pawn up. In that 'easy' to recognize draw from kramnik you put the black king on a7 and dang it's a zero. see my position example elsewhere. So your engine exchanges to a position with pawn down to reach somewhere in far horizon a draw score from eval. then when you get near that position it is simply a pawn down as it sees that position is tactical lost completely. This happens to be a lot of times the case in blocked positions. GMs are world champion winning blocked positions, let me tell you that... ...blocked positions that Omar scores of course each time as a draw :) >-S. > >>Omid. >> >>> >>>-S. >>>>Omid. >>>> >>>>> >>>>>>Omid.
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