Author: Robert Hyatt
Date: 07:59:55 04/30/04
Go up one level in this thread
On April 30, 2004 at 08:02:57, Uri Blass wrote: >On April 30, 2004 at 07:49:10, Vincent Diepeveen wrote: > >>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. > >I can only say that number of plies is meaningless. >It even does not mean that it is better in tactics. > >I can search more than 100 plies forward if I do enough reductions and every >move is reduced by at least 10 plies. > >I do not understand why do people discuss about it. > >Uri It gives them something to talk about when all their other arguments are based on fallacy...
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