Computer Chess Club Archives




Subject: Re: When to do a null move search - an experiment

Author: Robert Hyatt

Date: 20:22:26 04/29/04

Go up one level in this thread

On April 29, 2004 at 19:26:32, Ed Schröder wrote:

>On April 29, 2004 at 18:05:29, Omid David Tabibi wrote:
>>On April 29, 2004 at 09:28:53, Ed Schröder wrote:
>>>On April 29, 2004 at 07:37:23, Vincent Diepeveen wrote:
>>>[ snips ]
>>>>>This is all very poor Vince, I assume you don't play much with nowadays top
>>>>>programs. From 1982 to 2001 Rebel won its games by positional understanding and
>>>>>not by search and Rebel lost its games because it was outsearched. Today Rebel
>>>>>isn't outsearched at all, it now loses its games because the current top
>>>>>programs have a better positional understanding than Rebel.
>>>>>You should have a good look at the current tops, the positional progress has
>>>>>been great the last years. To me it all seems to indicate (provided your search
>>>>>is okay) the only way to make progress is to improve on chess knowledge. But
>>>>>what's new, I already came to that conclusion in 1986 after some intensive talks
>>>>>with Hans Berliner.
>>>>What i mean is Ed, is that you would not have accomplished the great results
>>>>with Rebel which you managed, had you just searched with a fullwidth search +
>>>>bunch of checks in qsearch.
>>>No of course not, brute force is silly, Rebel since day 1 has been a selective
>>>program. But I am getting your point, in the days before the nullmove was
>>>discovered Genius and Rebel had the best (static) selective search, a dominant
>>>factor in their successes, is that what you meant to say? If so, it is true.
>>>If only Frans had kept his mouth shut to Chrilly (Chrilly leaking nullmove in
>>>the ICCA journal) it is very likely Fritz would been the next Richard Lang still
>>>dominating all the rating lists and WCC's for the last decade. But Frans didn't
>>>and then all bets were off.
>>Donninger published the article in 1993. Before that, there were two other
>>publications dealing with null-move:
>Yes, nullmove as we use it today, the other 2 articles not.

Campbell's paper is _exactly_ as I do it today less the recursive nature.  He
specifically mentioned different R values and said more testing with R=2 was

IE the "null-move observation" was defined _exactly_ as we use it in today's
programs, for those of us that use it...

>>Beal, D.F. (1989). Experiments with the null move. Advances in Computer Chess
>>5, (Ed. D.F. Beal) , pp. 65--79.
>>Goetsch, G. and Campbell, M.S. (1990). Experiments with the null-move heuristic.
>>Computers, Chess, and Cognition, (Eds. T.A. Marsland and J. Schaeffer), pp.

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