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

Author: Tony Werten

Date: 14:49:43 11/20/02

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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 :(


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

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