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Subject: Re: Repitition detection

Author: Robert Hyatt

Date: 20:29:42 12/27/02

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On December 27, 2002 at 18:20:22, Bruce Moreland wrote:

>On December 27, 2002 at 16:51:14, Robert Hyatt wrote:
>
>>On December 27, 2002 at 02:52:43, Bruce Moreland wrote:
>>
>>>On December 27, 2002 at 02:06:25, Uri Blass wrote:
>>>
>>>>No
>>>>It is not always correct.
>>>>
>>>>Tscp believes that the position is the same if the empty squares are the same
>>>>In most of the games it cause no errors but there are cases when it can cause
>>>>stupid blunders.
>>>
>>>I suggest that the best way to do this is to make a small hash table and insert
>>>hash keys of previously seen positions into it when a node is entered, and
>>>remove them with the node is left.
>>>
>>>The table does not need to be large, since depth of search is not infinite.  A
>>>small table won't blow cache.
>>>
>>>It can be large enough that collisions are rare.  Collisions are handled by
>>>moving to the next element, anyway.
>>>
>>>The method works in multiprocessor implementationss with some overhead but
>>>without causing horrific bugs.
>>
>>What are you doing to prevent a processor searching one pathway of the
>>tree from seeing a repetition position from a processor searching a
>>completely different path in the tree?
>
>I use one table per processor.
>
>bruce


OK... basically what I do with the repetition list...




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