Computer Chess Club Archives




Subject: Re: Proving something is better

Author: Omid David Tabibi

Date: 13:04:55 12/18/02

Go up one level in this thread

On December 18, 2002 at 15:48:50, Bruce Moreland wrote:

>On December 18, 2002 at 11:20:58, Gian-Carlo Pascutto wrote:
>>On December 18, 2002 at 11:07:49, Omid David Tabibi wrote:
>>>Have you ever conducted any research? If so, you would have known that a
>>>researcher doesn't examine everything since the creation of earth, he takes
>>>something which is known to be better and tries to improve it.
>>Which is why you investigated Heinz's adaptive nullmove.
>>Oh, wait...
>>>I didn't think that someone will seriously claim that std R=3 is better than >std R=3; but now, I'd be glad to write another paper comparing those two, and
>>>also mentioning fixed time comparisons if people find it interesting. Because
>>>although not appearing the article, I have conducted tens of other types of
>>>experiments (including fixed time) and I _know_ that vrfd R=2 is clearly
>>>superior to std R=3.
>>'Everything you know is wrong'
>>Whether R=2 or R=3 is better depends very much on the search below
>>that nullmove. For a Crafty-style program (which Genesis appears to
>>be), R=2 is going to be superior over R=3. But you can't claim that
>>is a general truth.
>The data in the article strongly implies that for this program, R=3 is better
>than R=2.

I didn't publish comparisons between std R=3 and std R=2 because there was no
justification for doing so, from a scientific point of view. But that doesn't
mean that I haven't conducted self-play matched between std R=2 and std R=3. I
few months ago I even posted some of my impressions based on those experiments,
and claimed that for longer time controls the superiority of std R=2 over std
R=2 is not that significant. Nevertheless, std R=2 always performed better than
std R=3.

>I think that programs are different enough that if you are going to study
>various tweaks of null move, you start by thorougly investigating the vanilla
>In computer chess, almost every assumption is baseless, because the programs are
>different enough that you'll get different results.
>To hash qsearch or not?  Bob doesn't, I do.  In mine, it is *definitely* better
>to do it.  In Bob's, it is *definitely* better not to.  Who is right?  Both of
>Before I did *anything* with null move, I would first get baselines for all
>manner of R.
>I have done tests from R=1 to R=6, with fractional values in between.  I don't
>do them just once, either, I do them ever year or so, to make sure that things
>have not changed.  Straight R=2 is best, for me.

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