Author: Robert Hyatt
Date: 15:28:01 10/09/02
Go up one level in this thread
On October 09, 2002 at 18:25:05, Robert Hyatt wrote: >On October 09, 2002 at 16:46:09, martin fierz wrote: > >>On October 09, 2002 at 16:20:52, Robert Hyatt wrote: >> >>>On October 09, 2002 at 14:44:45, martin fierz wrote: >>> >>>>On October 09, 2002 at 14:23:03, Robert Hyatt wrote: >>>> >>>>>On October 09, 2002 at 13:28:50, Mike S. wrote: >>>>> >>>>>>Percentages, based on a large comp-comp database: >>>>>> >>>>>>Engine | #Games total W B | total eQE* W/eQE B/eQE >>>>>>------------------------------------------------------------------- >>>>>>Fritz 7 | 784 69% 72% 65% | 59% (#57) 53% 67% >>>>>>Chess Tiger 14 | 850 66% 71% 62% | 72% (#71) 73% 71% >>>>>>Shredder 6/-P. | 743 61% 65% 57% | 58% (#58) 63% 53% >>>>>>Junior 7 | 799 55% 58% 53% | 41% (#60) 25% ! 56% >>>>>> >>>>>>*) "eQE" = early queen exchange (within the first 10 moves) >>>>>> >>>>>>Fritz 7's white percentage after an early exchange of the queens was 53% only, >>>>>>compared to it's general white average of 72%! Remarkable also Tiger 14's result >>>>>>with black: Much better (71% to 62%) without queens. Desastrous was Junior 7's >>>>>>result with white when the queens were off the board soon: only 25% (in 30 games >>>>>>of that kind). >>>>>> >>>>>>It looks as if the engines each are very different, in how they depend on having >>>>>>the queen... with Shredder 6/-Paderborn showing the smallest impact. >>>>>> >>>>>>For games with Black against Fritz 7 or Junior 7 (and probably against others >>>>>>too for which I didn't search the statistics), it could be promising to have an >>>>>>opening book which favours eQE variants... But that of course must not have >>>>>>"wholes" in other (more common) lines, so it can't be done by simply generate an >>>>>>opening tree based on an eQE games database only. >>>>>> >>>>>>Regards, >>>>>>M.Scheidl >>>>> >>>>> >>>>>I don't think it is too surprising. It just highlights a weakness that programs >>>>>fail to understand >>>>>basic endgame ideas, and rely more on tactics than on knowledge to move along >>>>>thru a game. >>>>> >>>>>If a program has some basic holes in its knowledge about endgames, then removing >>>>>the queens >>>>>is going to highlight those holes. Or, the inverse, keeping queens on tends to >>>>>cover up those holes, >>>>>at least for a while. >>>>> >>>>>Programs that don't understand majorities, weak pawns, distant >>>>>majorities/passers, which minor >>>>>pieces work best with pawns in various configurations, the fact that pawns on >>>>>both wings give >>>>>better winning chances than pawns on one wing, etc, are going to have great >>>>>trouble with GM >>>>>players. >>>>> >>>>>I've given some examples of things I've had to fix after watching GMs pick on >>>>>the same hole >>>>>over and over. Today I don't see those huge holes cause me a lot of trouble >>>>>(yes I still have >>>>>holes, to be sure, but not the building-sized holes some "tactical" programs >>>>>possess..) and I >>>>>don't particularly care if queens come off early or not. If you hear someone >>>>>complain about >>>>>an early queen trade, you can rest assured they _know_ they have some serious >>>>>endgame >>>>>holes that need work... >>>>> >>>>>And you can also rest assured that after the kind of practice Kramnik has had >>>>>with Fritz, that >>>>>he _knows_ what kind of holes are there and he's going to park in them every >>>>>day, since they >>>>>can't be fixed due to match rules (stupid rules I might add). >>>> >>>>just wondering: what do you think fritz' problem is and how would you fix it? >>>>and do you think you could fix these problems in a single day? >>>> >>>>aloha >>>> martin >>> >>> >>>I don't think many problems are "single-day" deals nowadays. At least not the >>>ones I >>>have seen and/or fixed in my code. The first problem is figuring out what the >>>"hole" is. >>>The last major one I had was pointed out by a GM (Roman). He was patiently >>>waiting >>>for me to log on one day and could not wait to "get started". >>> >>>"Bob, you _must_ do something about this endgame hole. cptnbluebear has won >>>four >>>games in a row with the same theme." >>> >>>"what is it?" >>> >>>"Crafty thinks two connected passed pawns are much stronger than two isolated >>>passed pawns >>>in a king and pawn ending. But the king can stop the two connected passers >>>easily while a >>>lone king has great trouble with isolated passers, the farther apart they are >>>the harder they are >>>to deal with." >>> >>>That kind of thing. Not really hard to fix. Not really easy either. But the >>>hard part is finding >>>what is wrong (recognizing it) rather than fixing it. That is a place where a >>>GM "helper" can >>>make a _huge_ difference. >>> >>>Fritz (and most commercial programs) are tuned in coarse ways. Big passed pawn >>>bonuses. >>>Big king safety bonuses. Take away those two features, and it has trouble, >>>because it doesn't >>>seem to understand that a majority will turn into a passer one day, but since >>>the search can't see >>>the passer it doesn't consider it at all. Controlling open files is fine. _if_ >>>the file is useful and >>>_if_ you _really_ control it. I've seen more than one program park a rook on >>>(say) the open >>>E file, even though black can block that file at will with a bishop. The rook >>>can't go to the >>>7th because Be6 locks it in. But it is as happy as a pig in slop with that file >>>even though it can't use >>>the squares on the opponent's half of the board in any way. >>> >>>General knowledge. With specific failures. Kramnik is exploiting this >>>ruthlessly... >> >>yes, i can see that. but my question was directed at your "stupid rules". if the >>problems in fritz are not simple fixes, as you seem to admit, then what would >>the fritz team gain by being allowed to toy around with the program? i don't >>know if i would dare to change anything in a well-tested engine in the middle of >>a match without time for testing :-) > > >There are things to tweak anyway. IE "be more aggressive" so that it will play >differently in the second pair of games than in the first, assuming you lose the >first pair. Or "be less aggressive". Or other such things. The main thing is >to >_not_ become too predictable, as that is the kiss of death against a strong GM. > > > >> >>also, when you write "fritz & commercials are tuned in a coarse way", does this >>imply you think crafty or any other program is tuned better? Missed that one. No. What I mean is that the commercial programs are _really_ tuned to play against other commercial programs. Often that simply requires a new piece of knowledge with a relatively big score. IE Fritz seems to over-evaluate weak pawns. Kramnik showed it that sometimes three isolated pawns are _not_ a weakness at all. Yet against computers, the idea Fritz does is probably perfectly acceptable. Too bad you couldn't listen in on the many GM conversations I have had, where they pick up on a specific thing (bishop pair too valuable, bishop pair not valuable enough, connected passers too valuable, etc...) Because once they see that, look out... And Kramnik has had a _long_ time to see it, and the program can't be changed to make it behave differently... >> >>aloha >> martin
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