Recalculate history for remaining moves after each search

Discussion of chess software programming and technical issues.

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Sergei S. Markoff
Posts: 227
Joined: Mon Sep 12, 2011 11:27 pm
Location: Moscow, Russia

Recalculate history for remaining moves after each search

Post by Sergei S. Markoff »

Is it worth to try?
If remaining depth > 2 plies, every search could potentially change history values for remaining moves — because moves for current side could reappear at ply + 2 — so, theoretically, we can improve ordering using data from already searched subtrees.
The Force Be With You!
F. Bluemers
Posts: 880
Joined: Thu Mar 09, 2006 11:21 pm
Location: Nederland

Re: Recalculate history for remaining moves after each searc

Post by F. Bluemers »

Sergei S. Markoff wrote:Is it worth to try?
If remaining depth > 2 plies, every search could potentially change history values for remaining moves — because moves for current side could reappear at ply + 2 — so, theoretically, we can improve ordering using data from already searched subtrees.
I have played with the same idea to reorder the moves after 4moves had been searched.
Alas this did not help much,i guess the benefits are to small to overcome the extra cost.
Maybe its more effective to use moves further on in the killerlist (ply+2)
for less reducing or reordering.
Best