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Subject: Re: Avoiding book moves when out of book question

Author: Robert Hyatt

Date: 07:11:36 07/08/01

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On July 08, 2001 at 10:09:04, Robert Hyatt wrote:

>On July 07, 2001 at 10:07:40, Brian Richardson wrote:
>
>>Hi
>>Tinker scores book moves (w/l/d formula) and also uses a preferences file (?
>>move flags) to avoid certain book moves, but only when in book.  Sometimes the
>>last possible book position has no book moves that Tinker would play with these
>>constraints, so it falls into the normal search.  Unfortunately, sometimes the
>>normal search picks one of these book moves it already tried to avoid.  Book
>>moves flagged ? can simply be removed from the root move list (when not leading
>>to check/mate issues), but how do others avoid book moves merely scored as poor?
>>Thanks
>>Brian
>
>
>I don't do anything about this at the present.  I tried a few things but
>all were worse.  IE you _could_ generate your ply-1 move list, and delete
>the moves that are in your book file.  For me, this was horrible.  Imagine
>a case where your opponent plays BxN, the only recapture is QxB, but you
>lose that game and flag the move as bad.  Now you just end up a piece down
>as that move can't be played.  It is better to propogate that "bad score"
>back up the tree a bit.
>
>One thing I should do that I am not (yet) is that if all moves at this ply
>are not playable, then I should back up and make the move two plies back
>not playable for the same reason.  And this should be done recursively to
>back up to a point where there are options...
>
>Bob


I should add that with my current book learning, if _all_ moves at a ply are
unplayable, then the move two plies back _should_ also be unplayable due to the
way I back up scores in the learning.  But this is not (yet) guaranteed to
happen.



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