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Subject: Re: move ordering

Author: Omid David Tabibi

Date: 07:21:12 05/11/03

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On May 11, 2003 at 07:19:04, Tim Foden wrote:

>On May 10, 2003 at 21:23:00, Omid David Tabibi wrote:
>
>>On May 10, 2003 at 20:32:10, Matthias Gemuh wrote:
>>
>>>On May 10, 2003 at 17:49:01, Mike Siler wrote:
>>>
>>>>When Sjeng finishes a search, it displays among its stats a move ordering
>>>>percentage. Does anyone know how this is calculate?
>>>>
>>>>Michael
>>>
>>>
>>>In most programs, it is the ratio FailHigh_on_fist_move/All_FailHighs.
>>>
>>
>>Why not use a more general figure:
>>ratio of "first move being the best" / "all (interior) nodes" ?
>
>I think this is because there are generally 2 types of interior nodes... one's
>that do fail-high, and ones that don't fail-high.
>
>In the ones that fail-high, we are very interested on the fail-high happening on
>the first move.
>
>In the ones that don't fail-high, we generally fail-low (due to alpha+1=beta),
>we don't (in general) have a best move.  And it will make hardly any difference
>what order we search the moves in, as we will have to look at them all anyway.
>

That's true, but my point is that we shouldn't confine the figure only to
fail-high cases, but also consider other nodes which produce a best move.
Anyway, the total figure will not vary significantly.


>Cheers, Tim.



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