Author: Vincent Diepeveen
Date: 04:49:10 04/30/04
Go up one level in this thread
On April 29, 2004 at 09:28:53, Ed Schröder wrote: >On April 29, 2004 at 07:37:23, Vincent Diepeveen wrote: > >[ snips ] > >>>This is all very poor Vince, I assume you don't play much with nowadays top >>>programs. From 1982 to 2001 Rebel won its games by positional understanding and >>>not by search and Rebel lost its games because it was outsearched. Today Rebel >>>isn't outsearched at all, it now loses its games because the current top >>>programs have a better positional understanding than Rebel. >>> >>>You should have a good look at the current tops, the positional progress has >>>been great the last years. To me it all seems to indicate (provided your search >>>is okay) the only way to make progress is to improve on chess knowledge. But >>>what's new, I already came to that conclusion in 1986 after some intensive talks >>>with Hans Berliner. > >>What i mean is Ed, is that you would not have accomplished the great results >>with Rebel which you managed, had you just searched with a fullwidth search + >>bunch of checks in qsearch. > >No of course not, brute force is silly, Rebel since day 1 has been a selective >program. But I am getting your point, in the days before the nullmove was >discovered Genius and Rebel had the best (static) selective search, a dominant >factor in their successes, is that what you meant to say? If so, it is true. That's what i mean, using a simple form of search in those days meant fullwidth. >If only Frans had kept his mouth shut to Chrilly (Chrilly leaking nullmove in >the ICCA journal) it is very likely Fritz would been the next Richard Lang still >dominating all the rating lists and WCC's for the last decade. But Frans didn't >and then all bets were off. Frans' world title in 1995 had a huge positive impact. > >>I am under the impression that you just like diep try checks at several depths >>in the qsearch. In diep i can try at the entire 32 ply of the qsearch checks. > >Checks in QS are relative cheap nevertheless I have limited them more and more >the last years. There is little sense doing long range QS checks if you already >hit 12-14 plies. I see that different, but i must add the note that Rebel is basically tactical selective in main search already and DIEP isn't. I do very little extensions in diep other than singular. Even check hardly gets extended, i'll extend it when it's singular. > >>Doing things like attacks in eval and mobility and scans for all kind of things >>which are trivial for chessplayers and i do not even dare to write down the name >>for here, they slow down once engine. > >>I would search 3 ply at 1991 hardware with it, simply because the code size is >>so huge, the nps at 1991 machine (i had a 10Mhz XT at the time) would be around >>a 100 nodes a second or so. > >You are overreacting of course. Well of course when programming for a 10Mhz machine i would add huge selectivity too, but i'm just talking about a theoretical math here now. My code size doesn't even fit within the ROMs you had in 1991 :) >>My point is would you have become world champion in 1991 searching 3 ply? > >8-10 plies was sufficient. 8-10 plies at 10Mhz with for its time a great eval is really a grandmaster piece of work. I actually was not so long ago at a friend of mine (IM) having a chessmachine with inside an Ed Schroeder program. I really was amazed that you got such a depth out of such a tiny hardware! In fact it completely outsearches diep 1997 which got 8 ply at the world champs 1997 at a PII300Mhz. > >>I very deliberately ask it this way, because fritz3 (1995) searching at todays >>hardware handsdown would search 20 ply in any middlegame, when it would be >>converted. Apart from that it single cpu would search 3.5 million nodes a second >>hands down. > >20 plies? >Come on. No kidding. Huber clearly has proven that with MTD and a simple eval (basically material) you can search depths of 30+ ply. The passive way in which fritz3 developed its pieces is very helpful. You get *everywhere* nullmove cutoffs. With an agressive tuned engine such a thing is of course a lot more difficult to do, if not nearly impossible at todays hardware. > > >>Todays fritz searched in 2003 world champs at a quad xeon 2.8Ghz about 13-15 >>ply. >> >>The 2003 fritz at a 386 , 10Mhz would have a problem getting beyond 4 ply. > >I don't believe that. In 1999 fritz searched 17 ply everywhere at a quad xeon 500Mhz in middlegame. In 2003 fritz at a quad xeon 2.8Ghz searched 14 ply in middlegame. Those 14 ply from fritz2003 however completely destroy that 17 ply from fritz1999. I know why this happens. I see it at many engines including DIEP. > >>Would you beat it with Rebel-Madrid? > >Fritz3 was a weak program, in tactics and positional play. Fritz5 was a >revelation, excellent search for those days (the nullmove era starts here) still Fritz3 won the world champs 1995, so for its day it can't have been too bad. >Fritz5 was positional weak. Rebel at that time was typically out-searched by 2-3 >average, it had to win its games by positional play. Then from Fritz6,7 and 8 >Fritz slowly became an excellent positional player. >And regarding Rebel at 1991, don't get too exited, you can't imagine the number >of holes in its selective search at that time. I'm sure there were huge holes, but search depth in those days were more important than it is now. >My best, > >Ed
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