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Subject: Re: Repeatability (questions for Omid)

Author: Martin Giepmans

Date: 19:19:24 12/18/02

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On December 18, 2002 at 21:51:20, Omid David Tabibi wrote:

>On December 18, 2002 at 21:44:09, Martin Giepmans wrote:
>>>>I don't understand what you are trying to say.
>>>>Without a research (if the verification search with reduced depth doesn't
>>>>give a cutoff) verification search would be pointless.
>>>The verification search goes deeper than the null-move search, so it might find
>>>tactical errors overlooked by the null-move search, and correct them (without
>>>any need for a re-search).
>>No need for a research ??????????
>>It's late, I guess we are talking about two different things?
>No we aren't :-)
>When we have a fail-high report, we simply reduce the depth, and continue a
>regular search, as if nothing has happened. Because this regular search (which
>can be called verification search) goes deeper, it might find out threats beyond
>null-move search's horizon. In that case, you would get the correct result even
>if you don't do a re-search!
Yes, we _were_ talking about 2 different things :)
My thing is verification search, yours is what I would call "de-extension".
One difference is that de-extensions are symmetrical (you reduce depth for
both colors) while (standard) verification search is essentially asymmetrical.

I think it's possible that at least some of the readers of your article
got confused here and implemented something in their programs that you
didn't intend. Perhaps that explains why in many cases your method didn't
seem to work.


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