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Subject: Re: Using just Upperbounds and Lowerbounds

Author: Robert Hyatt

Date: 18:30:58 02/04/01

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On February 04, 2001 at 12:00:23, Miguel A. Ballicora wrote:

>On February 04, 2001 at 10:46:32, Robert Hyatt wrote:
>
>>On February 04, 2001 at 04:50:34, Alvaro Jose Povoa Cardoso wrote:
>
>[deleted]
>
>>>If I'm not mistaken you said _internal_iterative_deepening_ can be used to fill
>>>the PV below this point. Can you explain the details, you see I'm a novice on
>>>this things.
>>>
>>>Alvaro Cardoso
>>>
>>>
>>
>>
>>I don't use it to fill in the PV. But if I reach a node where I am trying to
>>find a PV (using PVS I detect this where beta != alpha+1 in the search) and I
>>don't have a hash-table move to search, I do a short iterated search to find the
>>best move so that I can try it first and not have horrible move ordering.
>>
>>All I do is say "(1) is this a PV node (beta != alpha+1) and (2) do I not have
>>a hash move to search here?"  If the answer to both is yes, I simply call
>>search with the same position and ply, but depth-2.  However, _that_ search
>>will have the same problem so it too will again call search with depth-2-2,
>>and so forth...
>
>I am curious, would depth-1 take much time?
>
>Miguel

I tried 3 cases...   depth-1, -2 and -3.  -2 seemed to produce the best
results back when I tested it.  -1 was ok, just slower.



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