Author: Uri Blass
Date: 12:48:27 05/23/01
Go up one level in this thread
On May 23, 2001 at 13:46:30, Robert Hyatt wrote: >On May 23, 2001 at 11:55:29, Bruce Moreland wrote: > >>On May 22, 2001 at 13:07:29, Robert Hyatt wrote: >> >>>Rh5 seems better although I couldn't get DB Jr's score of +1.5 in any reasonable >>>time (two hours or so). >>> >>>I guess this leads to Uri's question (again) of "does Bxg7 actually win or >>>not?" >> >>My program liked Bxg7 in a minute or two, with a score of around +1, but it is >>speculative. >> >>It has not been tuned for this position. It had Bg7 Kg7 Ne5 and I don't >>remember what all after that. >> >>I went out for a while and when I came back it had Rh5 with a fail-high. This >>morning it is at +1.24, same thing. >> >>I'll leave it running for a day or two and see what happens. >> >>bruce > > >It seems obvious that all the programs like Rh5. The worry is that this is >a possibly bad move on a deep enough search, although I don't believe this >myself (yet). > >Kasparov seems to think that Bg7 is best. But when he says 'best' I am not >sure what that means, exactly. IE 'forced win'? 'good prospects'? Etc. And >of course he _could_ easily be wrong, although I would tend to not think this >is the normal case... > >Your 1.24 is getting closer to DB Jr's score than mine reached, although I >didn't let it run overnight. Think I will crank it up and let it burn for >a while myself... Interesting also to know how much time per position does Crafty need to get 11 out of 13(I say 11 out of 13 and not out of 14 because it seems that the Bxg7 is not correct so I do not count this position as a good test suite unless the solution is Rh5). I believe that Deep Fritz on slower hardware can get something like 7 or 8 out of 13 on PIII450(20 minutes per position). It could solve 1-5,7,8 but I did not give it enough time to find if it is going to change it's mind in all of these cases. It could also find the right move in 9 but changed it's mind and it seem to fail to solve it because of null move problems. It changed it's mind after more than 20 minutes on PIII450 so I may consider it as solved on pIII450(20 minutes per position) I did some analysis and found that later in the tree after Rd6 Rxd6 Nxd6+ Kd7 Nb5 Ng7 h6 Deep Fritz has fail low,fail high, fail low, fail high... and can never see things that Crafty has no problem to see. It is clearly a null move problem for Fritz because if I put selectivity=0 it does not show the same problem. The information of the results of deep blue Junior does not prove that Deep blue was really better in tactics than the top programs of today because of the following reasons: 1)Tactics in games is different than tactics in test suites and a program can be better at test suites when it fails to see tactics in games. 2)It is possible that there are some software improvement in Deep blue Junior and that the deep blue Junior that was tested is better than the deeper blue that played against kasparov. Uri
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