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Subject: Re: Move ordering at root

Author: Robert Hyatt

Date: 08:05:30 04/05/04

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On April 04, 2004 at 22:20:35, rasjid chan wrote:

>On April 04, 2004 at 14:10:43, Robert Hyatt wrote:
>
>I do what Renze is doing as I have fails outside window bounds, but I have
>not monitored how often it fails low at root below alpha.

fails outside window do not give good scores.  To see this clearly, run an N-ply
search and print the moves out with their "fail-soft scores".  Then rerun to the
same depth, but after searching each move, set alpha and beta back to +/-
infinity so that you get a true score for each move.  Compare the ordering.  It
will be _significantly_ different...


>
>Is it found that often there is no scores to sort on?

Just wrong scores....

alpha/beta fails high on a reasonable move, not always the best move...

>
>Rasjid
>
>>On April 04, 2004 at 08:12:50, Renze Steenhuisen wrote:
>>
>>>
>>>Lectori salutem!
>>>
>>>I was wondering how others are doing the re-ordering at the root-node after an
>>>iteration has completed? Because there are some different option actually...
>>>
>>>I was doing a very simple way of re-ordering, by just ordering them according to
>>>the returned scores in descending order (Best Score First, Worst Score Last).
>>
>>How do you get a score for any move other than the first move?
>>
>>>
>>>The first move to be searched is the best move found on the previous level,
>>>sounds logical to me, but what next? I would say that it may pay-off to first
>>>search the moves that were best in earlier iterations, before searching the rest
>>>of the never-found-to-be-best moves. Finally to have the moves ordered by the
>>>returned score.
>>>
>>>Is this correct? Can I get some good advice on this point? Thanks!
>>>
>>
>>
>>
>>I don't see where you can get scores to sort on.  I use node counts for each
>>sub-tree produced by each root move...
>>
>>
>>
>>
>>
>>>Cheers!
>>>   Renze



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