Author: Chessfun
Date: 12:18:51 02/06/04
Go up one level in this thread
On February 06, 2004 at 15:03:49, Uri Blass wrote:
>On February 06, 2004 at 14:29:30, Thorsten Czub wrote:
>
>>On February 06, 2004 at 12:19:09, Uri Blass wrote:
>>
>>>Here is the line of the game that you posted
>>>
>>>14...Qc7 {-0.30/18} 15. Bxh6 gxh6 {-0.40/15} 16. Qxh6 Rfd8 {-0.54/16}
>>>17.Rd3 Nh7 {0.00/17} 18.f4 Bf8 {0.01/18} 19.Rg3+ Kh8 {0.01/18} 20. Qh5 Rab8
>>>{0.35/17} 21.f5 exf5 {0.85/16} 22.Rf1 Rd7 {0.84/19} 23.Rxf5 f6 {0.84/18
>>>
>>>You can see that shredder evaluated the position as 0.54 pawns for itself at
>>>move 16 and it is more than 0.30 pawns for itself at move 14.
>>
>>right. right.
>>but it is 18 searches deep !
>>
>>in move 20 (that is 12 searches away from Qc7 it feels negative, and in move
>>21 even morenegative.
>>
>>how can the program oversee this, when it sees the things different within
>>12 plies later.
>>
>>>I believe that not pruning could not help shredder to avoid Qc7 and I am also
>>>not sure if it was the losing error(I suggested 17...Ne8 instead of 17...Nh7).
>>>
>>>Uri
>>
>>shredder itself changes the score from + into minus within a few moves.
>>
>>in between there is the fritz-like 0,00.
>>
>>if shredder itself sees now the weakness, why wasn't it able to see the obvious
>>move earlier ? it pruned it away-
>>if the move was wrong, why the score dropping ??
>
>I believe that the following claims are correct:
It could also be the horizon combined with pruning.
>1)The move Bxh6 was wrong but shredder blundered later(I suggested 17...Ne8
>instead of 17...Nh7)
I also looked at that move when Thorsten first posted and again it was another
move it took a long time to pick over Ne8.
I think even later though Shredder 8 still had better chances. Especially around
move 30.
>2)Shredder searched 15.Bxh6 to reduced depth but this is not the reason for
>playing 14...Qc7(otherwise shredder could see a drop in the score immediatly
>after 15.Bxh6 and it did not happen)
I honestly don't see either 14...Qc7 or 15. Bxh6 as the cause of the loss. It
does though get very complicated after Bxh6 and again the horizon sometimes can
cause the engine to move towards a line that isn't so good. Especially when it's
king is exposed.
When Thorsten posts the PGN with depths and times we probably can answer some of
the questions better as to what was the cause. It could be Shredder spent so
much time in the opening and short middlegame that it had little time left by
the time say move 33 came around.
Sarah.
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