Author: Sune Fischer
Date: 08:17:05 12/12/02
Go up one level in this thread
On December 12, 2002 at 10:06:05, Vincent Diepeveen wrote: >the selective version searched on average 2 to 3 ply deeper >than the diep paderborn 2002 version. > >So i was hoping for a big score improvement. My regret was big >when i figured out that the selective search version was getting >20-25% less in score than the paderborn 2002 version. > >Only then i realized clearly that the search depth of the selective >version, which at for example 14 ply could prune up to 7 ply >positional, that this version basically saw tactics deeper and >not so much positional deeper (of course to get decent mainlines >i toyed some but that's not representative for 99.999% of the lines). Yes I believe that. Again getting deep is no problem, but getting deep on the right lines is. Uri has some ideas he says, and unlike so many others he actually demostrates that they have some merrit. I think this is more impressive than someone coding for 10 years, claiming to have found the holy grail of evaluation, impemented it and is still getting beaten by "stupid", "factor 2 slower" open source programs. ;) In this case it's pretty much put up or shut up. If Diep has more knowledge than anyone (according to yourself, right?), then why isn't Diep the best in the world? I think this pretty much goes to show that there is _more_ than just evaluation at work here. <boldface> And this it is not the same as saying knowledge isn't important.</boldface> ;) >It has taken over half a year for me to conclude then that just >searching tactical deeper makes no sense at all. It's about >positional search depth nowadays, not tactical. Ah, so you didn't conclude the "right thing" at first then :) >Therefore i completely disbelief any theory that there are better >search algorithms than the current ones existing with regard >to computerchess. You are throwing away a big area of research, you should be putting just as much effort into this as in the evaluation, IMHO. >And that's that many things which for sure do not work anymore >are getting tried by some big amateurs now. > >incremental move generation is one of them. Ever realized why >no commercial program uses that anymore? I'm not so sure about that, can you really speak for everybody? IIRC Christophe said not long ago he generated one move at a time! >>Actually, I think it won't be long before Movei is whipping the floor with Diep. >>Then you can take all your fansy patterns, all your SMP and simply get >>out-pruned and out-extended by 200 lines of Uri brilliancy ;) > >I want to bet for a big amount of money and i give 2 to 1 that >in a match in 2004 the program Movei will not win a long match >against diep at say 6 games 120 0 level? > >Of course it is a bit unfair to give the movei only 2 years to >implement 2000 lines of code to improve his evaluation, but >well 2000 lines of evaluation for a chess program i >could possibly write within a week. Well, I would love to take that bet, but I can't promise Movei only has 2000 lines of eval in 2004 :( Once you start adding it grows rapidly. >I've got some tens of thousands to bet for. Lemme know when we >can appoint things! LOL, trying to scare me, are you? >>Classic mistake IMO, you want to throw a lot of patterns into the evaluation >>thinking this is how humans do it and so it must be good for computers too. >>It is easy to prove you wrong, as no computer has 100000 patterns, yet they >>still kick GM's butt. > >No it is easy to proof me right because all commercial programs and also >strong amateurs have put in a lot of extra chess knowledge the last years. > >I do not understand why you do not realize that. I am sure even Uri can >proof this to you very clearly. They do not deny it even. Instead at >computerchess events, where i by the way never see your face, they >loudly discuss it. > >Brutus is an ultimum try from chessbase of course to create a program >with a lot of knowledge. they put the knowledge in hardware which causes >it to evaluate way quicker than i can do in software. > >So brutus is a very dangerous program. It gets millions of nodes a second >at the loss of perhaps a factor 2 or 3 (because it has no hashtables >in hardware; note that to limit the inefficiency in hardware it just >searches 2 or 3 ply in hardware and not 4 or 5). > >I do not understand why people still are busy with 200 line evlauations >here when the truth is so clear here. I know why you can't understand it, it's because you are twisting what I've said. I said I believed evaluation came third, it's more important to have good pruning and extensions. Of course that can't be done without some kind of knowledge so.... What I mean to say is that my Extensions() is going to just as complex as my Evaluation(), if not more. My guess is evaluation is on average (measuring fullwith here) worth maybe 1-3 plies. I haven't done the experiment, but it would be an interesting experiment I suppose. You simply can't evaluate when a pawn is strong and going to promote in the middel game and only rarely in the endgame, you need extensions for that. When I look at most positions, as a chess player, I look for tactics, if there is no tactics I look for good positional moves and then "search" those for deeper tactics. I think that is pretty much the process, so tactics is of course always there. -S.
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