Author: Aivaras Juzvikas
Date: 01:23:17 03/24/04
Go up one level in this thread
On March 24, 2004 at 03:33:04, rasjid chan wrote: >Hi; > >I say nullmove generally works when done well as others have say the thingy >works miracles. >I may be calling nullmove with 3 pcs and not 12 piece cutoff. > >Here's my TSCP level strategy that may be wrong:- > >Nullmove means giving away a move which generally mean we are at >a disadvantage by not moving. But there are so called zugwang.... situations >where not making a move is the same. You see this often at endgames >when bishops criss-cross about and the pawns/kings are all at >different color squares so better to say "you are allowed 100 moves >and I don't move". So zome in on whether your side has good >moves to give away and not how many pieces you have. > >1) don't allow null move that immediately go into quiescent search >that has no captures / promote. It immediately evaluate() which is not too >good. check that the other side has at least 1 capture if it immediately go >into QS. > >2) My limit cutoff piece is 3 and not 12. I count that I have good moves >to give away otherwise I don't do nullmove.Any pawns that >can advance SAFELY is very good and count as 3 moves. Other moves count as 1. >bishop's move count as 0 to be safe near endgame. You may add other things >but you need codes that enable you to have the necessary information. > >3) I call eval() to check that the score is near cutoff before doing >nullmove. You can try counting if your side material is likely to be >good. > >4) I used reduction of 2/3; normal is search(depth - 1) >becomes (depth - 2 / usually 3). > >Hope it works for you as it works for others who claim it is so good. > >Rasjid thanx man, i did some minor changes but i guess the main change was not to use nullmove that immediatedly goes into qsearch and it worked! after 8 games it was clear that now nullmove version of my engine is better than the old one 5 wins 3 draws. i know i should play more games to claim that the new version of my engine is stronger, but hey its a promising start :)
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.