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Subject: Re: Check with Eduard

Author: Robert Hyatt

Date: 07:47:41 06/27/01

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On June 26, 2001 at 23:35:15, Uri Blass wrote:

>On June 26, 2001 at 23:06:26, Robert Hyatt wrote:
>
>>On June 26, 2001 at 14:29:25, Uri Blass wrote:
>>
>>>
>>>It also cannot be repeated against a chess program if it remembers the game and
>>>has learning by position or if it is not deterministic.
>>>
>>>Uri
>>
>>
>>This doesn't work quite like you think.  For lots of well-known reasons.  The
>>most important is that if you go out of book very early, and don't see anything
>>bad happening for a long while, it will take a _long_ while to propogate those
>>scores back up the search tree to avoid a bad early move that doesn't lose for
>>(say) 20 more moves.
>
>You can learn to remember scores of 0.1 or 0.2 pawns lower than the scores of
>the game after losing so if the program has a logical alternative it is going to
>choose it


As I said, it doesn't work like that.  Suppose that the first move looks like
0.00 when you search it.  And all the others look like -.3 at the same depth.
Your -.2 score will _still_ be the best, since you can't see deep enough to
discover that one of the -.3 moves will become +.3 in 4 more plies.

That is a "local maximum" and you can't work your way around it



>
>For example if it lost by 1.e4 c5 2.Na3 Nc6 when the score was 0.24 for itself
>After 2...Nc6  then it may remember only 0.04 for itself based on the fact that
>it lost the game and it may help it to prefer 2...e6 that gives it 0.17 pawns
>adavnatge for black.
>
>Uri

But suppose all the others are < .04?  you are stuck there.





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