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Subject: Re: Root move and incomplete iteration

Author: Robert Hyatt

Date: 13:08:26 12/11/00

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On December 11, 2000 at 15:00:36, Frank Phillips wrote:

>What is the standard approach to selecting the (root) move in an iterated search
>when time runs out part way through the next iteration at the next depth.  Going
>back to the pv for the last completed iteration sometime seems a waste,
>particularly with hash tables when it could have taken less than a second to get
>to that point and especially when the next incomplete iteration has a different
>root move.  Using the pv based on a partially completed search could be bad
>since had it continued a refutation might have been found.  Equally it could
>have turned out to good???..
>
>In my search I do not even start the next iteration is there is less than 50
>percent of the total allowed time left.
>
>Frank

I _always_ use the most recent result available.  And I don't avoid starting
the next iteration when I don't have much time left, because it is possible that
the next iteration will cause a fail-low, and trigger me to use more time.
Since a fail-low is a _fast_ search compared to a normal search, this is likely
to have enough time to happen.

However, it really depends on what you mean by "partial search result."  If
you mean that you don't completely search the _first_ move before you have to
make the move, it really doesn't matter.  If you mean you have _partially_
searched a different move after searching the first move, then no, you can
_never_ use a partial result from a single move.  The score will be wacky.



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