Author: blass uri
Date: 15:10:53 07/15/00
Go up one level in this thread
On July 15, 2000 at 17:40:00, Ralf Elvsén wrote: >On July 15, 2000 at 16:58:40, Pete R. wrote: > >>To take a different tack, I'm not particularly interested in the debate about >>whether DJ is GM strength or not. When I can set up a position on my home PC, >>and it can tell me as well or better than Kasparov can what the best move is and >>*why*, in terms I can understand, then there will be nothing important left to >>do in computer chess. But that's still a long way off, past the point when a >>home PC can supply enough horsepower to have a program beat the World Champ in >>match play. Playing good enough to win and understanding chess as well as a GM >>are two different things. And frankly from a commercial standpoint I'm more >>interested in training software that can do the latter, rather than just beat me >>up. >> >>In terms of DJ's performance, the question I'm musing about is whether a top of >>the line 8-way processor general purpose computer may be sufficient to do the >>job of beating humanity, subject to some lucky or brilliant tweaks in evaluation >>code. In other words, is the matter of coming up with better positional moves >>in blocked positions, thwarting wing onslaughts, etc. a matter of putting in so >>much *more* evaluation code that an 8-way server can't do the job? DB got >>around this by having massive amounts of eval parameters, all done in special >>hardware. But the recent performances, warts and all, of top multiprocessor >>programs begs the question of how much more horsepower is really needed. This >>is simply speculation of course, like most of these topics, but only the >>programmers would have a feel for whether they need another 1000 eval terms, or >>just better tuning. > >I have looked at most of Crafty's evaluation. Let me first say that >this is no Crafty bashing. I like the program. That said, the chess >content encoded is very crude. It is heuristics which may or may not >apply to the position in question. None of the little pieces of evalutation >does a better job than an average clubplayer. It is in combination >with the search it becomes so powerful. Of course I realize it is very >hard to balance such amount of code and I would fail miserably myself >if I tried. I am *not* complaining. > >I think we need many more plies >before the program can "teach" us what a position is really about, or >alternatively a much more precise (and slower) evalutaion. Since Crafty is >playing in the same division as the best commercials, I don't expect them to >have much more sophisticated evaluations. If they have, it hasn't given >then any superiority. > >Let me take this opportunity to ask someone who knows: Has Ed Schröder >chosen to add "everything" in Rebel's evalution. I might have misunderstood >some of his statements. He seemed to be disappointed that more chess >knowledge could give a weaker program in comp-comp games. I think that the main reason is that bigger knowledge does not know important things. It may be better than the default in small things but I do not know about cases when there is a big difference in the evaluation of a pawn between knowledge=25 and knowledge=500. I think that knowledge about cases whan a knight cannot move and maybe trapped is important and my observation is that knowledge=500 proably does not know it better. There are cases when you need some more plies to see that the knight is trapped by search(I saw a case when you need about 10 plies) but a good evaluation can tell you that the knight has no square that are not controlled by the opponent and give about one pawn panelty. This is only one example and there are other examples when it is important to include big positional scores in the evaluation. The difference between knowledge=25 and knowledge=500 is mainly in small positional scores and I believe that there is no difference or no difference in the big positional scores that are the important scores. Uri
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