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Subject: Reduction 2b and 2c

Author: Ed Schröder

Date: 02:30:45 12/30/02


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 :)



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