Author: Ed Schröder
Date: 09:08:19 08/27/00
Go up one level in this thread
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
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