Author: Uri Blass
Date: 13:14:10 09/18/05
Go up one level in this thread
On September 18, 2005 at 15:43:28, Chan Rasjid wrote: >On September 18, 2005 at 14:34:56, Uri Blass wrote: > >>On September 18, 2005 at 14:12:11, Chan Rasjid wrote: >> >>>This means there is NO-MATCH whatsoever with a 1 - 1000x nps difference. >>>Fruit's seems to sacrifice complicated (undue) evaluation in favour of high nps >>>and makes the top. >> >>I disagree >> >>Fruit has a very strong evaluation function. > >Firstly, I don't make definite statement but more of a guess, ie seems so to >me..The one think I have not examined yet in details is Fruit's evaluation. > >For your info, I think you made the same observations that I just found and >more of the secret of Fruit, ie data/structure organization, locality of >data,etc. eg. After I got the hint, when in domove(), I make(myself) copies of >board->sq[] for from, to, capture/ep with sqFrom, sqTo, sqCatureEP so that I >don't have cache jumping back to access board->sq[256]. Then I found Fruit does >the same. I believe the has an extra board->pos[256] for locality of data within >cache. > > >Strong evaluation may just mean good evaluation for:- >1) most basic standard stuffs that definitely do not harm, but gainful >2) b/r/ QUEEN mobility >3) attack king / king safety. > >Some others have full eval()for every pins. Does Fruit do any pins ? >If not then probably terms/factor wise, Fruit's evaluation is only professional >basic. > >> >>Most of the improvement from Fruit1.0 to Fruit2.1 is because of better >>evaluation. > >Of course eval() pays when optimal but after it is near optimal IT CANNOT >BE IMPROVED FURTHER. You can easily make it pays negative. >So we cannot be sure the reason Fritz, shredder lost is NOT because they wasted >critical time in pursuing complicated eval() that pays negative. >> > >>Crafty is faster than Fruit in nodes per second so nodes per second is not the >>secret of Fruit. > >By what factor , x 5 ? > >Ask Diepeeven. Crafty has a little evaluation (may be true comparatively ?) >and on bitboard which is not the way YET(?). > >I would bet generally if Crafty is just nps 3 x , it will outdo Fruit, provided >of course there are no major problems that the chess programming world is not >aware yet. The difference between fruit and Crafty is more than 3:1 speed advantage. > >> >>Uri > >I did this experiment, something like this:- > > if (board->ply_nb <= 16)// dont eval if above ply 16 > eval_piece(board,mat_info,pawn_info,&opening,&endgame);// mobility is here > > if (board->ply_nb <= 16)// dont eval if above ply 16 > eval_king(board,mat_info,&opening,&endgame); > > //passers allowed > eval_passer(board,pawn_info,&opening,&endgame); > > if (board->ply_nb <= 16)// dont eval if above ply 16 > eval_pattern(board,&opening,&endgame);// very simple stuff > >Those are fruit's major eval(). >It did not seem to weaken Fruit at all, wins ruffian,aristarch etc. > >Rasjid What time control did you use? At fast time control you do not get 16 plies in most lines. Uri
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.