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Subject: Re: q-search question

Author: Landon Rabern

Date: 11:00:16 07/19/00

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On July 19, 2000 at 13:22:47, Andrew Dados wrote:

>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-

I do not do checks in q-search.  The problem is that I should be missing fewer
tactical positions with SEE, than with just throwing all captures out where
attackerValue>defenderValue.

Landon



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