Author: Robert Hyatt
Date: 07:19:56 02/24/99
Go up one level in this thread
On February 24, 1999 at 08:15:09, Vincent Diepeveen wrote: >On February 24, 1999 at 06:57:57, blass uri wrote: > >> >>On February 23, 1999 at 18:53:28, Dann Corbit wrote: >> >>>On February 23, 1999 at 18:47:36, Vincent Diepeveen wrote: >>>>On February 23, 1999 at 14:53:11, Dann Corbit wrote: >>>[snip] >>>>>I don't think this is evidence of "cooking" -- more likely learning. Quite >>>>>likely, they have already analyzed this position set in their database and >>>>>therefore know the best responses for each position. >>>>> >>>>>Rather than indicating something underhanded, it probably just means that they >>>>>have run extensive testing in this area. Crafty would do the same thing. If I >>>>>ran crafty at very long time controls, it would update the learning data file >>>>>about what to do in these situations. Is crafty cheating? Certainly not. Not >>>>>'cooking' anything either. >>>>> >>>>>I don't see any evil conspiracy here. That does not mean there is nothing >>>>>afoot. But I doubt it. >>>> >>>>f5.32 gets shipped with Learning files already compiled for those >>>>positions and another few thousands for auto232 at the auto232 version, >>>>is that what u mean? >>>I only suspected something of that nature. But it certainly makes sense. If I >>>were a chess program manufacturer, I would have best move entries for thousands >>>of known difficult positions. Some of the Crafty and Covax postions turn up a >>>lot in games, for instance. >> >>I do not think that they used learning files already compiled for these >>positions >>because if they did it then they did not need to calculate moves when they >>played. >> >>They probably changed the evaluation function to have better results in the nunn >>match. >> >>Uri > >Well first look 'what kind of learning' do chessprograms have. >Chessprograms have only learning for bookmoves, and those are played at >once. All experiments with position learning at non-book moves failed so far, >commercially seen. I don't agree. I have spent more hours debugging stuff caused by forgetting about crafty's "position learning" than anything else. Because after a deep search it stores the result as a permanent hash entry that goes into a file. And when you play again, these 'learned positions' are loaded before doing anything. In my case, it wouldn't be hard to 'cook up something' for (say) the Nolot test to get 'em all right. And I would still do normal searches, but the 'scores' would be doctored by the permanent hash entries. > >So any kind of 'learning file' in the Nunn positions cannot be true unless >they play the move within a flash of a second (book move). > >The only thing that gets done is HARDCODING in the piece square tables >the position. Fritz3 was clearly provable cooking BK test set, >so much even that the b2-b4 position it played always b2-b4 if the >pawn structure in the centre matched. It even did it >when putting whites pawn from g2-g4 and blacks pawn from h7-h6. Then b4 is a big >blunder as black gets 2 passed pawns after Qc8, but still it played it. >all other chessprograms saw this within seconds, so would never play b4, >but fritz did. It just didn't like b4 initially, so i guess Frans gave it >so much bonus that it then always wanted to play b4, otherwise it got >death penalty... > >To quote someone: "the people just test positions at it to see how strong >programs are, so they ask for it". I'll not reveal his name, that would >not be nice. > >I think he is completely right however. > >Most programs, including crafty solve win at chess position 2, >at low depths just seeing that pawns get to 3d rank, where such >kind of evaluation is very dangerous. I don't think this is dangerous. My 'evaluation' is not "just a pair of connected passers on the 6th". It is more complex. And it was _not_ done for WAC2. It was done because in bullet games it would be well ahead and then lose when it allowed two connected passers to reach the point where a rook can't stop them. This has saved a _lot_ more games, and _won_ a lot more games, than it has lost. > >But abou the nunn positions: the only thing that can be done >in order to play these positions ok with >Fritz is to have new code implemented in the program that fills the piece >square tables. > >This is a clear case of cooking. > >Of course Nunn selected in the past only more or less closed positions, >as he got paid by chessbase. Later they even improved play here by doing >this. > >Greetings, >Vincent
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.