Author: Vasik Rajlich
Date: 04:30:41 02/20/05
Go up one level in this thread
On February 20, 2005 at 06:34:30, Sandro Necchi wrote: >On February 20, 2005 at 05:21:35, Vasik Rajlich wrote: > >>On February 20, 2005 at 04:40:19, Sandro Necchi wrote: >> >>>On February 19, 2005 at 07:43:49, Vincent Diepeveen wrote: >>> >>>>On February 17, 2005 at 14:03:30, Tord Romstad wrote: >>> >>>Hi Vincent, >>> >>>I hope everything is well with you. I guess you'll meet Stefan at Paderborn. >>> >>>> >>>>Don't do idiot experiments that just support the idiocy you invented yourself. >>>> >>>>IF you have an engine rated 3000 in strength THEN it will play virtually achieve >>>>2300 in the important games instead of 3000 when NOT using a book. So the book >>>>delivers 700 rating points. >>> >>>This is a very interesting statement. >>>I agree with you and I know that the stronger an engine is the best it will get >>>from a good opening book, but I never estimated how much it would get reaching >>>3000 in strenght. >>> >>>> >>>>Experiments with some idiot engine that is itself rated what is it, 2200, >>>>will be useless of course. >>>> >>>>Some years ago when engines were 2200 level it was the Mchess-Necchi team who >>>>said a book was worth 300, and he meant that obviously in the same way as i mean >>>>the 700 points at real high level. >>> >>>Yes, you are correct. >> >>So let me get this straight - if two equal engines play, and one of them has a >>book that decides one half of all games in its favor without any chance for the >>victim to continue, this books needs to be improved, since the rating boost here >>is only 200 rating points. > >A good book, to me should do the following: > >1. Give positions with a plus for the program. >2. Give positions which can show the best of the program strenght by allowing it >to play the strongest. >3. Play positions that bring to endgames the program know to play well. > >Now if 2 engines about strong the same reach a position which is better for >program a (suitable more for program a) program a will get an advantage soon or >later even if not higher in score from the opening and program b will not be >able to recover. > >The result is that in that game program a and b will not show to be about strong >the same. Do you understand what I mean? Sandro, yes, I understand what you say. Certainly, you can benefit from having a book which co-operates with your engine. I can believe that when you have an engine at the level of Shredder, every improvement helps. The question we're dealing with here is - how much does it help? Personally, I doubt that you can regularly patch up problems in the evaluation via book. Or that you can regularly exploit positional problems in your opponents via book. Or that you can just get forced wins in the opening on a regular basis. Of course, this is just a personal opinion. The question which Tord and Uri and Martin and Sune and now also me are asking is: what experiments support the claim that the book has a significant (ie. >=75 Elo) effect on the engine level? The answer that you must try playing in a WCCC with a top engine but without a book is not very satisfying :) Thanks, Vas > >> >>Some years ago I played something like 300-400 games is tournaments. From all >>these games, maybe 3 or 4 were decided in the opening - at least as far as I >>could tell. So I'm wondering what exactly I missed there ... > >In WCCC tournaments it is different as the operator is choosing the variations >and these are very selected. The selection is made also on the weakness of the >opponent and not only in our strenght. > >This is the difference of a hand made book compared to a book made from games >database. This would take about 1 hour or so, while I have been working on my >book since 27 years now and making improvements every day... > >> >>Vas > >Sandro > >> >>> >>>> >>>>The weakest link is what counts. >>>> >>>>I don't care for your engine in that respect, let alone such stupid experiment. >>>> >>>>Take a strong engine from which you feel it is the best engine in the world. >>>>Show up without book in important events. World champ will be the best test. >>>> >>>>THEN calculate after a 100 years of doing that, what the odds were you won that >>>>event. You will see it's 0%. >>> >>>Yes, here we agree too. >>> >>>Sandro >>>> >>>>750 rating points is roughly meaning that a person A has 0% chance against >>>>person B. >>>> >>>>What i'm saying is that not using a book versus an excellent book is making that >>>>difference true. 700 rating points. Not a point less. >>>> >>>>Vincent >>>> >>>>>A couple of days ago, a well-known programmer and regular >>>>>poster here on the CCC claimed that a good opening book >>>>>was worth at least 700 Elo points. I thought this number >>>>>looked completely outrageous, and decided to do a simple >>>>>experiment. >>>>> >>>>>I am the author of a basic and minimalistic UCI chess engine >>>>>called Glaurung. Source code and executables for Mac OS X, >>>>>Linux and Windows can be found at the following URL: >>>>> >>>>>http://www.math.uio.no/~romstad/glaurung/glaurung.html >>>>> >>>>>Recently, I have played some test matches with Glaurung >>>>>against the strongest engine I have on my compter: Hiarcs >>>>>9.6. Not surprisingly, all such matches end in crushing >>>>>victories for Hiarcs. The last match I played ended >>>>>75-25 in Hiarcs' favor. >>>>> >>>>>As a crude test of the "good book=700 Elo" claim, I have >>>>>now repeated the match with identical program versions >>>>>and conditions, except that Hiarcs was now playing without >>>>>an opening book. Assuming that Hiarcs' book is worth 700 >>>>>Elo, the expected result of this second match would be >>>>>something like 95-5 in _Glaurung's_ favor. >>>>> >>>>>The actual result of the second match was very close to >>>>>the first match: Hiarcs won by 72-28. >>>>> >>>>>As far as I can see, this means that at least one of the >>>>>following must be true: >>>>> >>>>>a) The statement "good book=700 Elo" is lightyears away >>>>>from the truth. >>>>> >>>>>b) Hiarcs has an extremely bad opening book, and with a >>>>>half decent opening book it would be several hundred >>>>>rating points ahead of Shredder. >>>>> >>>>> >>>>>Tord
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