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Subject: Re: root move ordering

Author: Robert Hyatt

Date: 18:09:33 09/22/04

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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...




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