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Subject: Re: Doesn't appear to work for me (full data)

Author: Omid David Tabibi

Date: 14:54:34 11/20/02

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On November 20, 2002 at 17:49:43, Tony Werten wrote:

>On November 20, 2002 at 17:31:57, Omid David Tabibi wrote:
>>On November 20, 2002 at 16:55:41, Gian-Carlo Pascutto wrote:
>>>Nullmove in Deep Sjeng uses an algorithm of my own, but I can
>>>switch it back to other systems easily. I did so for running
>>>a few tests.
>>>I made a version which uses Heinz Adaptive Nullmove Pruning
>>>and a version which uses your verification nullmove.
>>>I did a run over ECM-GCP, at 10 seconds per position.
>>>So, you can see here that verification nullmove searches 20% more
>>>nodes, took 12% more time, searched 1/3 of a ply less deep and
>>>missed three more positions.
>>>That's pretty much a 'total loss' :)
>>That is a typical result when the quiescence search is too big. With the help of
>>its extensions, even the standard version of your algorithm manages to detect
>>most of the problems that verified null-move is meant to detect. So the
>>verification search is just a waste of time in this case (and since your test
>>was conducted in a fixed time per position, this waste of time didn't enable the
>>verified version to reach deeper and detect what the other version did).
>>By shifting to a far simpler quiescence search, you will get about the same
>>tactical strength as you get currently (since this time, verified null-move will
>>detect the problems, instead of your immense quiescence), but will end up with a
>>significantly smaller search tree.
>And positionally a weaker program :(

You should play with it until you get a balanced quiescence search which is not
too big (does not pose a major overhead), but also retains the necessary factors
you need.

>>The quiescence search of Genesis which I conducted the tests on, consisted of
>>only captures/recaptures.

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