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Subject: Re: q-search question

Author: Andrew Dados

Date: 10:22:47 07/19/00

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On July 19, 2000 at 12:03:10, Landon Rabern wrote:

>I have been discarding all captures where attackervalue>DefenderValue in my
>q-search which speeds it up significantly, but I know that it is throwing away
>some captures that are good.  So I implemented a SEE function.  The SEE returns
>the correct value on tests I have run.  When I put this into my program so that
>if (attackervalue>DefenderValue)&&(SEE>=0) I keep the move as well, I got worse
>results on the WAC test suite.  Before I put the see in I got 270/300 at 60
>seconds per move and after I got 257/300 at 60 seconds per move.
>
>Is it just that there are no capture sequences in this test that need the extra
>captures, or is there something wrong with my SEE function?
>
>Thanks for any help,
>
>
>Landon W. Rabern

It would be of help if you post some relevant positions. I may just guess now
that if you do check detection in qsearch you may find some mating combinations
with 'losing captures', when recapturing piece is overloaded simply, so in next
move capture is mate. (Or you may do some non-capturing,checking moves in
qsearch which complicates matters still). With SEE you miss those. Question is
if average speedup of SEE in non-tactical positions offsets those few missed by
using SEE....

-Andrew-



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