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Subject: Re: An MTD(f) question about NULL MOVE searching

Author: Vasik Rajlich

Date: 06:28:09 07/16/04

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On July 16, 2004 at 09:21:12, Vasik Rajlich wrote:

>On July 16, 2004 at 09:13:07, Fabien Letouzey wrote:
>>On July 16, 2004 at 09:07:15, Aivaras Juzvikas wrote:
>>>as i understand a node is a pv node if beta != alpha + 1
>>Yes, but a PV node does not necessarily end up in the PV (e.g. fail high).
>>Therefore "PV node" and "PV" are different concepts.
>>I think Vasik was talking about null moves in the PV, and I gave my opinion
>>about this topic.  Maybe I misunderstood his post though.
>I am not sure I understand this distinction. Do you mean that PV node is a node
>which you score between alpha and beta, and PV is the variation which eventually
>emerges? (Ie pv nodes can be "overwritten")

Never mind - I understand now. Of course you should do null moves at PV nodes.
It's just that you only accept the score if it fails high (rather than with
score between alpha and beta). Yes, this is what I had meant in the first place
of course :)


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