Author: Robert Hyatt
Date: 19:05:14 08/27/00
Go up one level in this thread
On August 27, 2000 at 12:08:19, Ed Schröder wrote: >On August 27, 2000 at 10:05:17, Robert Hyatt wrote: > >>On August 27, 2000 at 00:28:08, Ed Schröder wrote: >> >>>On August 26, 2000 at 23:43:34, Robert Hyatt wrote: >>> >>>>On August 26, 2000 at 23:06:10, Ed Schröder wrote: >>>> >>>>>On August 26, 2000 at 21:08:37, Robert Hyatt wrote: >>>>> >>>>>>On August 26, 2000 at 11:05:24, walter irvin wrote: >>>>>> >>>>>>>On August 26, 2000 at 09:21:15, Robert Hyatt wrote: >>>>>>> >>>>>>>>On August 26, 2000 at 09:16:50, Uri Blass wrote: >>>>>>>> >>>>>>>>>I tried this position from the game century3-crafty17.11 >>>>>>>>> >>>>>>>>>[D]rnbqk2r/pp1p1ppp/4pn2/4P3/1b1N4/2N5/PPP2PPP/R1BQKB1R b KQkq - 0 1 >>>>>>>>> >>>>>>>>>Crafty17.13 played 6...Qc7 >>>>>>>>> >>>>>>>>>I gave my Crafty17.11 as engine for Hiarcs with 128 Mbyes hash time control of 4 >>>>>>>>>hours/60 moves >>>>>>>>>(I guess that this time control is similiar to 2 hours/60 moves on the alpha) >>>>>>>>> >>>>>>>>>My Crafty17.11 changed its mind in the last second at depth 12 from 6..Qc7(0.15 >>>>>>>>>pawn advantage) to the better move 6...Nd5(0.16 pawns advantage). >>>>>>>>> >>>>>>>>>I am interested to know crafty17.13's opinion. >>>>>>>>>Can crafty17.13 avoid 6...Qc7 at depth 12? >>>>>>>>> >>>>>>>>>Uri >>>>>>>> >>>>>>>> >>>>>>>>It avoids it by depth=10. The problem was that the mode we were using forced it >>>>>>>>to play Qc7 as it was a book move. Somehow we followed a very rarely played >>>>>>>>line, but until I get the log files from Graham I can't tell exactly why. I >>>>>>>>did notice a pretty significant CAP score that might have pulled it down that >>>>>>>>line erroneously... >>>>>>> >>>>>>>what was the speed relitive x86 for the alpha you used .would it have been >>>>>>>faster if you could have gotten similar hardware that deep junior had at >>>>>>>dortmund ??what nps was you seeing on the alpha . >>>>>> >>>>>> >>>>>>We were doing about 400K nps. My quad xeon does about 1M, for reference. >>>>>> >>>>>>Speed wasn't the issue here however, it was simply following a bad book line >>>>>>until it was too late... >>>>> >>>>>But 6..Qc7? came not from the book but from the Crafty engine. In this >>>>>game the Crafty book did not work. >>>>> >>>>>Ed >>>> >>>> >>>>No... it came from the book. We were using "book random 0" which says to >>>>search (for a short time, normally) all the book moves, and play the one with >>>>the best score. Qc7 was in the book, but the score fails low pretty quickly. >>>>Then, after resolving the fail low, it decides "hey, this is bad, I am not >>>>going to play a book move at all." It then does a normal search, but it had >>>>used too much time and the search wasn't very deep.... >>>> >>>>The book was actually working, but "book random 0" changes the way it looks, >>>>and if you don't know, you could assume it is doing a normal search, unless >>>>you see the line "searching only the following moves: {a b c d etc} >>>> >>>>I think Qc7 was the third most popular move in that very narrow (and bad) book >>>>line... >>> >>>This is what I remember from our game: 1.e4 by Rebel and Crafty immediately >>>replied with 1..c5 from the book. Then 2.Nf3 and then Crafty started to >>>think shortly (5-10 seconds) and the second Crafty move was played. This >>>behaviour (5-10 secons for the move) continued till move 5 or 6 and then >>>Crafty started to use the normal 2-4 minutes for its moves. 6..Qc7 came >>>at the last moment after a 2-4 minutes search. After 6..Qc7 Rebel was also >>>out of book. >>> >>>I don't know that much about Crafty but everybody was saying Crafty was >>>out of book after move 1. Also Graham said the above Crafty behavior was >>>the same in game 1 (implied Crafty playing without book in game-1). >>> >>>Hope this gives you sufficient information to make up your mind what >>>really went wrong with the book. >>> >>>Ed >> >> >>That sounds like what I would expect here... If the score for Qc7 dropped >>enough, it will refuse to play it as a book move and do a search. I had not >>factored in the problem with a fail low at the end of the book search, which >>could use over 1/2 of the total time allocated to this move. But I will cover >>this hole quickly, of course. :) >> >>Qc7 was played several thousand times, however, which makes it surprising it >>isn't in your book. > >Qc7 is a losing move just trash it from your book. Rebel had to find 7.exf6 >and sacrifice the rook on a1. I was happy Rebel did. After that the game was >over. I think Jeroen will add 6..Qc7? 7.exf6 to the book so Rebel can find >7.exf6 also on short time controls. After 7.exf6 things are easy to find. > >Ed The sad thing is that Crafty has played this vs GM players 10 times now. And it _won_ all ten games with black. That is why book learning had not already culled this silly variation. :) Learning doesn't cure all book woes unless the opponents punish it so that it learns it was punished. :) Creating a good book (automatically) is a challenge. If you only use GM games, the book is too narrow. If you use a bigger game collection, you get garbage moves...
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