Author: Martin Giepmans
Date: 10:56:05 08/08/01
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On August 08, 2001 at 13:22:03, Bruce Moreland wrote: >On August 08, 2001 at 12:30:47, TEERAPONG TOVIRAT wrote: > >> >>Hi, >> >>As I understand, a draw score from hashtable can be originated from >>1.an almost equal position 2.repetition of position >>Is it generally recommended to differentiate these 2 conditions? >>How much would I gain if I fix the problem? > >Rip out your hash table stuff, or at very least don't cut off based upon hash >table score. > >This is probably a bit too harsh, so another possibility is to ignore the >problem. > >It's not just the draw score, it's any score. If you never ever hash 0.00 or >cut off based upon 0.00 in the table, you will *still* have problems. > >Let's say you have to choose between two positions. Position A is +0.40. >Position B is +0.20. > >If you detect a repetition on A, your score for this search will be +0.20. If >you detect one on B, your score is +0.20. > >Neither of those is 0.00, but if you encounter this position when there is a >change in which move (if any) leads to a rep, you'll get an erroneous score. >You could return +0.20 when move A doesn't lead to a rep, and you could return >+0.40 when it does. > >So the bottom line is you are screwed no matter what. > >bruce > I don't understand this. In the circumstances that you describe position A and B will in my program both get E = 0.00. How could they get E = +0.20? And because the program never uses a drawscore from the hashtable for a cutoff (because it cannot know if this score is based on a repetition or not) there is no problem. True? Martin >> >>Thanks, >>Teerapong
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