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Subject: Re: new thoughts on verified null move

Author: Tony Werten

Date: 18:09:36 11/23/02

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On November 23, 2002 at 20:52:01, Omid David Tabibi wrote:

>On November 23, 2002 at 20:00:15, Tony Werten wrote:
>
>>On November 23, 2002 at 11:11:16, Christophe Theron wrote:
>>
>>>On November 23, 2002 at 09:22:37, jefkaan wrote:
>>>
>>>>oops, wasn't finished yet..
>>>>
>>>>>are done by using the results of the positional eval
>>>>>to prune the q-search,
>>>>and there using only material eval
>>>> (haven't tried it out yet, and wouldn't
>>>>know how to do it, but it's only an idea,
>>>>you know.. to explore options of
>>>>more effective branch factor reducements
>>>>and efficient programming (besides
>>>>lousy solutions as inline assembler
>>>>and bitboards..
>>>>:)
>>>
>>>
>>>
>>>Yes Chess Tiger does much more pruning than known (published) techniques.
>>>
>>>I think other top programs do it also.
>>>
>>>I still fail to see why the efficiency of an algorithm depends on what your
>>>QSearch does.
>>>
>>>If your pruning algorithm is good, it will increase the strength of the program
>>>regardless on how good your QSearch is.
>>>
>>>If your QSearch is smart, then it will increase the strength even more.
>>>
>>>I don't like the idea that some algorithms that have almost nothing to do with
>>>each other would have such an influence on each other. It is indeed possible and
>>>it probably happens all the time, but it's hard to work with such hypothesis in
>>>mind.
>>>
>>>I think it's better to first assume that the kind of QSearch you do will not
>>>interfere with the quality of the pruning algorithm used before the QSearch.
>>>
>>>If your QSearch sucks, it's not because you are doing a lot of pruning in the
>>>"full width" part of the search. It's because it sucks.
>>
>>The paper does prove that the more your (q)search sucks, the better your pruning
>>algoritm seems. But that's not really news.
>>
>
>Does it prove that?! No, it's just my impression based on the data gathered so
>far. Maybe a reduction of 2 (instead of 1) in case of fail-high report, will
>work better in programs with heavy extensions and quiescence.

A reduction of 20% seems to be working best in XiniX ( heavy qsearch). I'm
interessed in your idea. It's commented out in my program now, but not deleted.
I still have to play with it some more.

Despite of the negative comments you had, I don't think it's a bad idea. I'm
just not convinced yet it's a good one.

Tony



>
>
>>Tony
>>
>>>
>>>
>>>
>>>    Christophe



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