Author: Uri Blass
Date: 16:17:25 12/29/01
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On December 29, 2001 at 15:05:22, Sune Fischer wrote: >On December 29, 2001 at 13:59:25, Ed Schröder wrote: > >>On December 28, 2001 at 08:14:02, Uri Blass wrote: >> >>>if you extend the qsearch too much you may get >>>often irrelevant positions that you analyze. >> >>So? >> >>What you get back is an accurate score of the leaf, the only thing that counts. >> >>Limiting QS to 6,7... plies is a bad thing because it will return an unreliable >>score too many times. >> >>Ed > >It is not as bad as it sounds really, not if you sort them by MVV-LVA. >If I limit QS to e.g. 3 plies, then I can afford 1 ply extra for the whole tree. >OK, I don't use SEE now, maybe that will speed up QS enough so that is >affordable, but for right now my program is the overall strongest by using QS of >only 3 plies deep (I tested against itself). And actually it almost never begins >a losing capture sequence. >If I do a full QS then >80% of the time is spent in there, that is a complete >overkill IMO, since chess is not 80% capture moves. >It is very much a trade off, and dependent on the rest of the program. > >-S. My qsearch is not close to include >80% of the nodes and I suspect that you do something wrong in the qsearch. Here are the results of my program when searching depth 7 from the initial position: limit of qsearch in plies is the first number in every line and nodes for depth 7 is the second number: Note that it is using static evaluation when it finish the qsearch and it is not a smart thing to do I think that limiting the qsearch too much may do chess program slower in getting the same depth thanks to bad order of moves 0 2868842 1 3611982 2 997968 3 1564826 4 1196247 5 1214999 6 1184129 7 1153555 8 1180282 9 1153618 >=10 1153584 I also tried modified TSCP that use similiar techniques and got the following 0 1329080 1 2107731 2 1495776 3 1341166 4 1106628 5 1090297 6 1142271 7 1173772 8 1156489 9 1174336 10 1174570 11 1174435 12 1174560 >=13 1174526 I believe that you do something wrong if you get 80% of the nodes in the qsearch. note that my program and TSCP have no SEE. Uri
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