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Subject: Re: Quiescence vs swapoff

Author: Peter Fendrich

Date: 10:26:54 04/15/98

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On April 15, 1998 at 13:12:57, Christophe Theron wrote:

>On April 15, 1998 at 13:01:42, Peter Fendrich wrote:
>
>>I am trying a swapoff algorithm (sometimes called SEE) instead of the
>> more classic quiescence search.
>>The extra time saved by this can be used for more agressive extensions
>>or better evaluation.
>>The drawback is of cource the increased risk for tactical mistakes.
>>
>>In short depths the swapoff makes too many mistakes to be useful but
>>when the depth increases I see less of the mistakes but still have
>>that extra time it saves for me.
>>
>>In my opinion it should be a break even, at some depth limit, between
>>these two alg's and beyond that limit the swapoff is the best choice.
>>
>>Comments?
>>
>>/Peter
>
>The swapoff idea is the first thing that comes in mind when someone
>begins to write a chess program. That's how I begun, at least.
>
When I wrote my first chess program about 1980 SEE wasn't a known
concept, at least not for me!

>IMO it is not as fast as a simple QSearch. This is counterintuitive, but
>as depth increase, QSearch has less and less job to do, because there
>are more and more alphabeta cutoffs before or on entering in the
>QSearch.

The SEE code itself should be faster than Qsearch, shouldn't it?

>
>On the other hand, a SEE has always the same amount of job to do,
>whatever the depth is. In any case, more job than QSearch.
>
I dont't follow you here. If QSearch has less job to do, then the SEE
has as well. The QSearch is just replaed by the SEE.

>And I don't even mention the huge blunders you will never get rid off
>with your SEE, even if you make it very clever.
>
>Just my opinion, based on experience.
>
>Anyway, writting a good SEE is useful, because you can use it for
>selection purposes.

I have two versions of SEE, a fast one used to order generated captures
and one more accurate and slower to replace the QSearch.

>
>
>    Christophe



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