Author: martin fierz
Date: 02:46:13 02/27/04
Go up one level in this thread
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. all other programs participating in this tournament have not studied any 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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