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Subject: Re: Value of extension for pushing passed pawn

Author: Robert Hyatt

Date: 11:08:25 03/11/03

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On March 10, 2003 at 19:04:56, Will Singleton wrote:

>I also messed around with this one a lot, and found that on a push to the
>seventh, a full ply extension was best.  Sixth rank and other pawn extensions
>blew up the search too much, or else didn't help if fractional.
>
>The 7th rank extension helps me quite a bit in game play and test suites.
>
>Will


Remember that it is easy to make a single fractional extension "trigger"

I use 60 as a single ply, and several extensions are .75 ply values, which
turns into 45 in my fractional ply measuring.

When you do an N ply search, rather than setting "depth_remaining_ to N*60,
you can set it to N*60+30, which means that the _first_ two 3/4 ply extensions
will actually extend the search by two plies rather than 1.5, since you have
that
.5 ply bias in from the beginning and any extension >= .5 will cause it to roll
to
the next whole depth.



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