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Subject: Re: "Don't trust draw score" <=Is it true?

Author: Bruce Moreland

Date: 10:22:03 08/08/01

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On August 08, 2001 at 12:30:47, TEERAPONG TOVIRAT wrote:

>
>Hi,
>
>As I understand, a draw score from hashtable can be originated from
>1.an almost equal position 2.repetition of position
>Is it generally recommended to differentiate these 2 conditions?
>How much would I gain if I fix the problem?

Rip out your hash table stuff, or at very least don't cut off based upon hash
table score.

This is probably a bit too harsh, so another possibility is to ignore the
problem.

It's not just the draw score, it's any score.  If you never ever hash 0.00 or
cut off based upon 0.00 in the table, you will *still* have problems.

Let's say you have to choose between two positions.  Position A is +0.40.
Position B is +0.20.

If you detect a repetition on A, your score for this search will be +0.20.  If
you detect one on B, your score is +0.20.

Neither of those is 0.00, but if you encounter this position when there is a
change in which move (if any) leads to a rep, you'll get an erroneous score.
You could return +0.20 when move A doesn't lead to a rep, and you could return
+0.40 when it does.

So the bottom line is you are screwed no matter what.

bruce

>
>Thanks,
>Teerapong



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