Author: Uri Blass
Date: 01:46:01 12/30/01
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On December 30, 2001 at 04:14:40, Sune Fischer wrote: >On December 29, 2001 at 20:19:45, Uri Blass wrote: > >>>I think R. Hyatt said crafty spends 50% of the time in QS. >> >>I think that it includes the time that Crafty spends on evaluation function. > >Yes, what else? > >>>I'm not counting nodes just the time, the program just runs 3-5 times slower to >>>the same depth (for the base tree) when it does a full QS. >> >> >>It means that you probably have some bug. >> >>The program should run faster to the same depth when you do qsearch because of >>better order of moves. > >I do not hash the qnodes. >But the move ordering can be improved, I know. > >> I don't understand >>>why this is so unexpected, say there are two possible captures at every leaf >>>node on average after I stop my QS at depth 3. Then that alone is 3 times as >>>large a tree, and there could be more captures after that! >> >> >>There are captures that should not be analyzed because they are not good enough. >>If you are a rook down and capture a pawn when alpha=0 then you can avoid making >>the move because you can know that it is not good enough. >> >>I can guess that your problem may be that you make these captures only to >>evaluate them later and discover that they are bad. >> >>Maybe my guess is wrong and your problem is different. > >I'm not sure, I'm doing exactly what Bruce has explained here: >http://www.seanet.com/~brucemo/topics/quiescent.htm The algorithm as described there make unnecessary moves. I evaluate moves before I make them and the algorithm that is described does not do it. For me makemove and generating all the attack tables cost time so I prefer to do it only after verifying that the capture is good enough. Guessing the evaluation of a capture without making it is easy(I can find easily exact score with a simple evaluation but even after I do my evaluation more comlicated I can get a good estimate for it based on material and use the estimate to avoid generating unnecessary captures). Uri
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