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Subject: Re: Move ordering at root

Author: rasjid chan

Date: 09:27:50 04/05/04

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On April 05, 2004 at 11:05:30, Robert Hyatt wrote:

Thanks, but I don't need to test yet as you have tested !

I think using nodes searched should be good.
If a move fails low with very few nodes searched, it probably
mean being rejected easily, so sort low.

Rasjid




>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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