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Subject: Re: root move ordering

Author: Stuart Cracraft

Date: 19:17:10 09/22/04

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On September 22, 2004 at 21:09:33, Robert Hyatt wrote:

>On September 22, 2004 at 20:55:37, Stuart Cracraft wrote:
>
>>On September 22, 2004 at 19:38:53, Robert Hyatt wrote:
>>
>>>On September 22, 2004 at 18:53:51, Stuart Cracraft wrote:
>>>
>>>>Are you saying I should consider marking each move after its search, then
>>>>back up the score value, node count, etc., then resort based on that?
>>>>
>>>>I could see that various parts of the subtree have generated new history
>>>>heuristic scores for from/to move coordinate pairs and that a resort could
>>>>affect the remaining move order.
>>>>
>>>>I don't currently resort at any level after the movegen at that level.
>>>>I just search all the moves in the original post-movegen-sort-order.
>>>>
>>>>I am fine with considering doing continual resorts but worry about the
>>>>overhead and the return. But with it being the all important move-ordering,
>>>>what have you seen in doing these resorts in terms of improvement
>>>>
>>>>Stuart
>>>
>>>There is _no_ overhead.  It is done only at the root, once per iteration.  For a
>>>12 ply search, a total of 12 times.  That won't use measurable CPU time.  The
>>>point is that root move ordering is critical for efficiency..
>>
>>That's a new one on me. I always thought it was throughout the tree. I'll
>>have to chew up some code on this one.
>
>
>Ordering is important everywhere.  But this thread was about ordering at the
>_root_ of the tree...

I will try it.



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