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Subject: Root Search Question

Author: William Bryant

Date: 21:07:47 12/26/99


If your search fails low on the root PV move.
(IE. the full alpha beta window for the PV move returns a score <= alpha
and nothing is backed up into the PV array).

Do you?

1) Stop PVS and search the rest of the root moves for this iteration with a
	full alpha beta window?

2) Stop PVS until at least one move for this iteration falls into the alpha
	beta window. If no moves fall into the window, research the whole
	iteration with a lower window. (fail low).  This means that you may end up
	searching every move with a full alpha beta window which would take more
 	time before the fail low occurs.

3) Stop now and lower the window and research with PVS.

4) Do Nothing?
	Continue the rest of the root moves within the -alpha-1, -alpha PVS window.
	Only search moves outside the PVS window for the rest of this iteration
	if they return a score > alpha on the PVS search.  Hope that if the
	every root move is going to fail low, that this will speed up the
	search until the window is lower.

5) Suggest something better.

Fail low on the root move seem to bring my search to a crawl and I'm looking
for a way to be more efficient.

Thanks in advance.

William
wbryant@ix.netcom.com




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