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Old March 24th 04, 01:13 PM
Mike Gleason Jr Couturier
 
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Default Where do I increment the history table

In the AB search function, I read different things
about where to increment the the history heuristic...

Is it when val = beta

Or when val alpha

Or just before returning at the end of the search
function ? I have seen all three.

Also, do I need to reset the counter to zero after
the board state has changed a lot (after a couple of
moves...) ?

Thank you !


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Old March 24th 04, 03:44 PM
Robert Hyatt
 
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Default Where do I increment the history table

Mike Gleason Jr Couturier wrote:
In the AB search function, I read different things
about where to increment the the history heuristic...


Is it when val = beta


Or when val alpha


_both_. Just not when val == alpha...


Or just before returning at the end of the search
function ? I have seen all three.


You only update the counter when you either (a) return a value val that is
= beta, or (b) return a value val that is alpha and beta...





Also, do I need to reset the counter to zero after
the board state has changed a lot (after a couple of
moves...) ?


You at least need to "age" the values downward periodically to avoid overflow...




Thank you !




--
Robert M. Hyatt, Ph.D. Computer and Information Sciences
University of Alabama at Birmingham
(205) 934-2213 136A Campbell Hall
(205) 934-5473 FAX Birmingham, AL 35294-1170
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Old March 24th 04, 08:27 PM
Mike Gleason Jr Couturier
 
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Default Where do I increment the history table

Thank you very much !

Mike


"Robert Hyatt" wrote in message
...
Mike Gleason Jr Couturier wrote:
In the AB search function, I read different things
about where to increment the the history heuristic...


Is it when val = beta


Or when val alpha


_both_. Just not when val == alpha...


Or just before returning at the end of the search
function ? I have seen all three.


You only update the counter when you either (a) return a value val that is
= beta, or (b) return a value val that is alpha and beta...





Also, do I need to reset the counter to zero after
the board state has changed a lot (after a couple of
moves...) ?


You at least need to "age" the values downward periodically to avoid

overflow...




Thank you !




--
Robert M. Hyatt, Ph.D. Computer and Information Sciences
University of Alabama at Birmingham
(205) 934-2213 136A Campbell Hall
(205) 934-5473 FAX Birmingham, AL 35294-1170



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