Author: Ed Schröder
Date: 21:28:08 08/26/00
Go up one level in this thread
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
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