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Subject: Re: Rebel's plus sign during analysis

Author: Ed Schröder

Date: 20:55:02 08/02/98

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>I've always done this.  The problem is that on some occasions, the null-
>move search can cause a "false-fail-high".  The re-search produces a score
>that was worse than the old search, or, more commonly, actually fails low.

>I reject such fail highs if the re-search is worse than the old best (I
>catch this by searching with (old-best, +infinity), so that if I fail low,
>I know it is worse than the old best move and it gets rejected outright.

>I've had versions where this was "broken" for various reasons, and they
>always produced an occasional bizarre-looking move that could be an outright
>blunder, or just a slightly weaker move...

Hi Bob,

Glad to hear a "false-fail-high" is common practise -:)

Like to add that I often have noticed such a "false-fail-high" is rewarded
in the next iteration after all. It has puzzled me for years. A few years
ago I made a test-version that always took a "fail-high" as best move,
false or not. Results were not better but also not worse.

Similar experiences?

- Ed -



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