Author: Matthew Hull
Date: 06:08:51 02/27/04
Go up one level in this thread
On February 27, 2004 at 05:46:13, martin fierz wrote: >On February 26, 2004 at 23:08:28, Robert Hyatt wrote: > >>On February 26, 2004 at 17:42:43, martin fierz wrote: >> >>>On February 26, 2004 at 14:59:55, Robert Hyatt wrote: >>> >>>>On February 26, 2004 at 04:37:37, martin fierz wrote: >>>> >>>>>On February 25, 2004 at 22:42:08, Robert Hyatt wrote: >>>>> >>>>>>On February 25, 2004 at 18:40:06, Bas Hamstra wrote: >>>>>> >>>>>>>On February 25, 2004 at 13:46:22, Robert Hyatt wrote: >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>What book are you using for Crafty? >>>>>>>> >>>>>>>>It will _never_ play 1. g3 as white with any book I have ever distributed. Not >>>>>>>>that it is a bad move, but it suggests that something is way wrong with the >>>>>>>>setup you are using for Crafty, at least. >>>>>>>> >>>>>>>>Aha. I see you are using the fritz powerbook with max variety... >>>>>>>> >>>>>>>>That begs the question of what your "tournament" is supposed to show, since a >>>>>>>>wide book introduces _lots_ of luck into the outcome, and won't be reproducible >>>>>>>>by anyone else since nobody uses one common book for multiple engines... >>>>>>> >>>>>>>What do you mean "nobody"? Everybody does do it all the time! And a wide book is >>>>>>>even better, it shows what your search-object (engine) is capable of in a wide >>>>>>>variety of positions, in stead of playing over and over and over the same few >>>>>>>"proven" openings. If Crafty is mated in 12 moves in an irregular opening, >>>>>>>wouldnt' that be interesting to know? Think about it. >>>>>> >>>>>>Not if that opening is 1. g3, which neither it nor I (nor most anybody) will >>>>>>play. Ditto for the 1. f4 openings, the 1. b4 openings, etc. >>>>>> >>>>>>I don't write code to handle such cases, if I never expect to have to play them >>>>>>over the board... >>>>>> >>>>>>Now if you choose _reasonable_ openings, that might be another matter. But I >>>>>>don't particularly like 1. g3 and after having played chess for 40+ years as a >>>>>>human, I _still_ don't ever play that opening... >>>>>>> >>>>>>> >>>>>>>Best regards, >>>>>>>Bas. >>>>> >>>>>i think bas is very much right. i test with nunn2 positions. these cover a lot >>>>>of variety, closed and open positions, positions with opposite-side castling >>>>>etc. you get a better idea what an engine can do if you test lots of different >>>>>positions, and also what it can't do! >>>> >>>>And once you learn that it can't do something (say a hyper-modern type opening) >>>>very well, what then? I just say "don't play that opening" and go on, and maybe >>>>when I have time, at some point in the future, I might address that. IE it was >>>>a long time before I would let Crafty play any fianchetto sort of opening as it >>>>didn't understand how critical the bishop is to defend the weak squares caused >>>>by the g3/g6/b3/b6 pawn push. Once I fixed it, I allowed those openings. But >>>>until I did, I did not. I would call it silly to make an old program of mine >>>>play such openings, because I _already_ know that it will do badly with them. >>>>What is the point of seeing that again? >>> >>>that's not the point. if crafty can't handle a position with the fianchetto, >>>then odds are it probably doesn't understand how to play against it either... >> >>Actually, it plays _against_ it very well. It just does the usual "sieze the >>center and break it open." But once you have played g3, you don't really want >>to see any e4 type stuff as it creates weaknesses, so the "occupy the center >>with pawns" and such is wrong. >>> >>> >>>>>i don't understand your take on the opening moves. 1. g3 is a sound move. 1. b4 >>>>>is slightly weird, and 1. f4 is really weird. >>>> >>>>I think f4 is pretty good, in fact. >>> >>>once again, that is where our chess rating difference comes from :-) >> >>Not sure what you mean. Should I point you to some GM games with 1. f4? :) >>I have several thousand. > >fine, you can believe what you want of course. you can also try to count the >number of games that kasparov, karpov, kramnik, anand & co start with 1.f4. or >the number of games played in world championships starting with 1.f4. or go and >ask some of your GM friends what they think of 1.f4... > > >>But I am talking about _computer_ games. And against human opponents, 1. f4 is >>really not a bad opening at all, as white's f4 move is an aggressive move in >>many cases from the Sicilian to the King's gambit.. > >err, now you are changing the subject rather radically. we're talking about >1.f4, which is a crappy opening. playing f4 at a later stage, when the position >is completely different is a rather different matter :-) > >of course, if you play 1.f4 with crafty against humans then i would say it's >fine if you get a king's gambit e.g. if the opponent replies to 1.f4 with e5 and >you go 2.e4. but why not start out with 1. e4 and play king's gambit against e5 >than? > > >>>>But while g3 is perfectly sound, white is >>>>saying "I am going to play on the wings in many variations (while in others you >>>>might see a quick d4/e3/etc of course). And my program simply doesn't like that >>>>idea very much. >>> >>>same answer as above: if you can't play one side of an opening, you probably >>>can't play the other either. >> >>I totally disagree. There is a difference between playing defensively, and >>playing to attack a defensive player. Ditto for a player that eschews the >>center. I don't have to play such openings well, in fact I don't even have to >>like them at all, in order to play against them from the other side... > >i totally disagree too. if not having the center is such a problem for crafty, >it will evaluate all positions against such a passive opening as being just >great for black, when in fact they are not - they will be about equal. having a >way-off eval for these positions can give strange results; e.g. you will get >into bad positions thinking they are good for you because you have a bit more >central control. > > >> >>> >>> >>>> >>>>>i also wouldn't want to test too >>>>>much with moves like 1. f4 or 1. g4; but 1. g3 is fine - it mostly transposes to >>>>>some regular opening with fianchetto like some form of catalan or english, which >>>>>are good, solid openings. it definitely qualifies as reasonable! >>>> >>>> >>>>Depends on your definition of "reasonable". "sound opening"? Yes. But >>>>"sound opening for a program that doesn't like the resulting positions at the >>>>moment?" No. >>>> >>>> >>>> >>>> >>>>> >>>>>finally, i have played openings that are slightly unsound just to learn about >>>>>the resulting positions (e.g. queens gambit tarrasch defence to learn about >>>>>IQP). you can stop playing them again later, but you will have learned something >>>>>you can apply in similar positions arising from other openings. for engines the >>>>>same: if crafty cannot handle positions that come up after 1.g3, there is some >>>>>kind of problem in crafty.... >>>> >>>>Perhaps the problem is already known? And discovering it a second, third or >>>>fourth time is not exactly going to reveal anything new... That was my point. >>>>That is why I release books with my engine. I consider a chess program to be a >>>>combination of engine, book, endgame tables, configuration files, and the like. >>>>Change any one of them and the "program" is now "different". IE I'll play you >>>>as many games as you want (human to human) but if you ask me to play 1. g3 I'm >>>>not going to comply. I have other openings I like far better. :) That is the >>>>idea here, IMHO. It makes no sense to force the program to play something it >>>>doesn't "like". >>> >>>you are thinking of maximizing playing strength only. what if i wanted to use >>>crafty as analysis module in chessbase? i would want it to make reasonable >>>suggestions in all openings! i never use chess engines to play against. i always >>>use them to analyze. >> >> >>I am only considering playing computers against opponents. Nothing more or >>less. So you are correct in that regard... But when tournament results are >>reported here, do you really think people say "hey, that program did pretty well >>playing an odd variety of openings" or "hey, that program got beat pretty >>badly"??? :) > >no, of course they will say the second. i just don't like the entire approach. >there are many cop-outs i know of in computer chess, like all those tricks with >thinking "many pawns on the board = bad position for me", or your trick of not >taking something on g5 even if it's for free. or the famous "fritz won't take >free pawns on e4 because of mr. nemeth" thing. these are the extremes. this >example is less extreme, of course. but still: chess is chess, and programs that >don't know how to handle certain positions will always be susceptible to some >form of attack. take kasparov-X3d fritz, game 3. most chess programmers try to >solve the problem of closed positions by hoping their opening book will stop >them from getting into such positions. and when it happens, BOOM, there goes >your 2800 rating and even 1800 is still too much... i'd rather try to fix the >problems in my eval than continuously fix the opening book. > > > > >> >> >> >> >>> >>> >>>>Do you think you could coax anything but 1. d4 out of (say) Korchnoi, when the >>>>game is important?? >>> >>>certainly. Nf3 and c4 at the very least. modern top grandmasters play >>>everything, every single one of them. there are very few GMs who stick to a very >>>narrow repertoire (eg sveshnikov, lputian), and none of them is in the very top. >>>coincidence? >> >>Missing the point. Do they play _random_ openings? Or do they play openings >>they have studied and prepared at home, often for specific opponents. Hint: It >>is _not_ random... > >hint: crafty has not studied any openings. GM's don't play random openings well. They play their repetoire well. Same with programs. >all other programs participating in >this tournament have not studied any openings. The programmers have studied them. The goal is to build a system that will win, not to build a system that will win with inferior openings. >i'm pretty sure that if another >strong program was at the bottom of the standings, it's programmer would use the >same excuse :-) >i'd say that 30 games are not enough to be significant and leave it at that... > >cheers > martin > > > > >>>cheers >>> martin >>> >>>> >>>> >>>>> >>>>>cheers >>>>> martin
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