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Subject: Re: Rebel's plus sign during analysis

Author: Ernst A. Heinz

Date: 00:14:03 08/03/98

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On August 03, 1998 at 02:21:12, Amir Ban wrote:
>
>I always accept the fail-high move immediately.
>
>There are parameters that you are important that you don't mention: What size
>window is used during normal search ? If it's zero-width, or very small, then
>fail-high doesn't mean it's much better than the previous best, and you can take
>the new move or leave it. If you use a 0.3-0.5 window, as I do, fail-high means
>it's clearly better than the previous, even it later fails low.
>
>Also, what window do you use on the re-search that fails low ? If you use
>new-alpha+1 to infinity, then maybe the fail-low happened because the value is
>exactly new-alpha. If you use a window of old-alpha to infinity, then a >fail-low
>indeed makes the move suspicious.
>
>Amir

Good point, Amir!

Actually, I do not recall to having encountered the fail-low after fail-high
behaviour as long as the research is done with the *old alpha*, i.e. the
same that was used when the fail-high occured.

Otherwise, this nasty fail-low after fail-high behaviour unfortunately
seems to occur quite frequently.

=Ernst=



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