Author: Robert Hyatt
Date: 20:43:34 08/26/00
Go up one level in this thread
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...
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