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Subject: Re: About qsearch...

Author: Sune Fischer

Date: 12:05:22 12/29/01

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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.




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