Author: Nolan Denson
Date: 17:13:25 07/24/02
Go up one level in this thread
Thanks for the Info On July 24, 2002 at 19:10:09, Mike Byrne wrote: >On July 24, 2002 at 17:14:48, Nolan Denson wrote: > >>Ok from some post that Mike made i realize that i can change the extension >>values of crafty .... but I am still not sure whats going on. >> >>As you can see from below the singular ext for Matrix is set at .58 ... I am >>not sure if this is bad or good ... So if i wanted to change this value what >>would the command be or where in the code does the rest of this get change at. >> >>I notice that mike changes these values via the crafty.rc file. Where are these >>values actually effecting crafty ?? Which part of the code ?? Then if anyone has >>an understanding of the code for singular extension and know where those values >>are ... please post also. >> >>Like i said I am not a programmer ... (but I am learning alot about it by doing >>these kind of things) .... I want to change the .58 to a different value, and >>run some test to see what happens. At the end of this message i posted the code >>for singular extensions as well. Also do you guys that know about this think >>that the .58 is too low or too high? Mike changes his values via the following >>commands : via the crafty.rc >> >>booster 76 76 225 >>ext in 1 >>ext th 1 >>ext one .75 >>ext pawn .75 >> >> >>one-reply extension..................0.75 >>in-check extension...................1.00 >>recapture extension..................0.75 >>pushpp extension.....................0.75 >>mate thrt extension..................0.75 >>singular extension...................0.58 >>one-reply extension..................0.75 >>in-check extension...................1.00 >>recapture extension..................0.75 >>pushpp extension.....................0.75 >>mate thrt extension..................0.75 >>singular extension...................0.58 >>one-reply extension..................0.75 >>in-check extension...................1.00 >>recapture extension..................0.75 >>pushpp extension.....................0.75 >>mate thrt extension..................0.75 >>singular extension...................0.58 >>one-reply extension..................0.75 >>in-check extension...................1.00 >>recapture extension..................0.75 >>pushpp extension.....................0.75 >>mate thrt extension..................0.75 >>singular extension...................0.58 >> >> >>Matrix v99.99 (2 cpus) >> >>White(1): ext >>one-reply extension..................0.00 >>in-check extension...................0.00 >>recapture extension..................0.00 >>pushpp extension.....................0.00 >>mate thrt extension..................0.00 >>singular extension...................0.58 >> >> > > >Hi Nolan - > >It's easy to change the extensions via the crafty.rc file. There was a change >fron Crafty 17 to Crafty 18 ... > >Crafty 17.xx used the following > >ext in (in check) >ext th (mate threat) >ext rec (recapture) >ext p (pawn push) >ext one (one response) > >Crafty 18.xx >ext ch (in check) >ext ma (mate threat) >teh other are the same in Crafty 18.xx > >The allowables value are from 0 to 1. Crafty uses partial extensions - so >value of 1 will extend 1 ply if the condition is met. A value of .5 will extend >a 1/2 ply. Crafty also cuts extension in half when the increment depth is > 2 >ply. Generally , the default values have been .75 or 3/4 ply. I usually >prefer the either the in-check or threat (or both to be set at 1). If you start >adding extension, you generally have to lower the number. Very high numbers may >do well in certain positions - but it can do horrible in other positions if >there is a "lot" going on. > >I used to be very high on the recapture extension, but with the faster hardware >and the quiesce rountine - I am not convinced it always needed - but there are >certainly some positions that it helps - in other positions it just helps to >blow up the search. > >There is no one right answer - I usually prefer them to be higher. > >Mike
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