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Subject: Re: Move ordering at root -, oups

Author: Gerd Isenberg

Date: 13:31:41 04/05/04

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On April 05, 2004 at 16:29:00, Gerd Isenberg wrote:

>On April 05, 2004 at 15:51:43, Robert Hyatt wrote:
>
>>On April 05, 2004 at 15:02:56, Gerd Isenberg wrote:
>>
>>>On April 05, 2004 at 14:11:34, Robert Hyatt wrote:
>>>
>>>>On April 05, 2004 at 12:27:50, rasjid chan wrote:
>>>>
>>>>>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
>>>>
>>>>Correct most of the time.  Sometimes a move will have a high node count just
>>>>because there are lots of checks and extensions.  But I've been sorting by node
>>>>counts for 15+ years with good results, of course forcing the PV move to always
>>>>be at the top regardless of its node count...
>>>>
>>>
>>>I use node count per root move too.
>>>What about following "enhancement":
>>>If PV changes, to store (some) "previous" PV moves and to use them early after
>>>current PV move, regardless of their node counts?
>>
>>
>>It is worth testing.  It didn't work for me in crafty or Cray Blitz, but it
>>might work for another program.  I always had the best luck overall by just
>>using pure node counts...
>>
>>It helps the most when there is a "best" move that you won't find until deeper
>>depths.  It will percolate up the list, iteration by iteration, so that it is
>>near the top on the iteration where it becomes best.  I also use this
>>information in my parallel split/dont-split at the root adaptive algorithm in
>>Crafty...
>
>
Yes, exactly my experience. Anyway i occasionally noticed a former PV move had
low node count (e.g. a forced draw line) but a new PV move suddenly fails below
draw score. Im such cases trying the "safe" drawline earlier may help to save
some time.



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