Author: Peter Fendrich
Date: 14:09:33 12/30/02
Go up one level in this thread
On December 30, 2002 at 14:52:30, Dave Gomboc wrote:
>On December 30, 2002 at 05:53:16, Martin Giepmans wrote:
>
>>On December 30, 2002 at 05:30:45, Ed Schröder wrote:
>>
>>>As it seems I have completely mishandled explaining Reduction 2b and 2c, I have
>>>corrected things.
>>>
>>>http://members.home.nl/matador/chess840.htm
>>>
>>>Click on the blue "update" picture, it will move you directly to the changes
>>>made. That will be standard procedure from now on in case of errors.
>>>
>>>if (remaining_depth<=x && remaining_depth>1) then
>>> { if (ALPHA < SCORE + THREAT) -> do not reduce
>>> if (ALPHA < SCORE + THREAT + MARGIN) -> reduce depth with one ply. }
>>>
>>> SCORE : score of EVAL
>>> THREAT : Queen=900, Rook=500, Bishop=300, Knight=300, Pawn=100
>>> MARGIN : TABLE [remaining_depth];
>>>
>>> static int TABLE[]= { 00,00,10,15,20,25,25,25,25,25,25,25,25,25,
>>> 25,25,25,25,25,25,25 ........... };
>>>
>>>The idea is, if SCORE+THREAD are not going to make it to ALPHA, but with an
>>>extra small MARGIN it will then reduce the depth. I can't remember the speed-up
>>>this reduction gave.
>>>
>>>====
>>>
>>>Ed
>>>
>>>PS, the "faulty stuff" plus Uri's correction is maybe worth a try, who knows :)
>>
>>The < in the second formula should be > ?
>>Otherwise the two formula's together don't make sense.
>>(if the first is true, the second is also true)
>>
>>Martin
>
>I think it's:
>
>if ((remaining_depth <= x) && (remaining_depth > 1)) then
> { if (ALPHA < SCORE + THREAT) -> do not reduce
> *else* if (ALPHA < SCORE + THREAT + MARGIN) -> reduce depth by one ply. }
>
>Dave
Yes, that's about how I read it.
Ed is doing it in assembler so my guess is something like:
{ if (ALPHA < SCORE + THREAT) -> do not reduce + exit
if (ALPHA < SCORE + THREAT + MARGIN) -> reduce depth by one ply + exit }
Peter
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.