Author: Peter Kasinski
Date: 17:55:16 02/22/99
Go up one level in this thread
On February 22, 1999 at 20:16:36, Will Singleton wrote:
>
>So most of us need 9 plies due to the fact that the mating attack isn't seen
>till then. However Zarkov (ply 7) and Crafty (ply 8, I think) see it earlier,
>and Crafty specifically doesn't use qsearch checks. So I'm wondering how they
>see it earlier? Some other extension, or null-move threat detection?
>
>For comparison, MacChess 4.0 also needs 9 plys, but Hiarcs 6 only needs 6 plys.
>
>This occurs again in the analysis for black's reply. Zarkov sees the score jump
>at ply 6, where EXchess and Amateur must wait until ply 8. And Zarkov uses
>fewer nodes.
>
>Some other points:
>
>I think I'm extending too much. I got a 17-move pv in plys 7-8, and no one else
>showed anything much above 12 moves. But seventeen is unusual. And it didn't
>help at all, either, I still had to wait for 9 ply. So, Bob's point about the
>qsearch being limited in value might be something for me to follow up on.
>
>Pedestrian never changes to Nf5 in the middle plys, unlike some of the others.
>Is it using some method to inhibit the good score achieved by the others, or
>what? Might be helpful for him to run the second position, to check that.
>
Well here is the second position:
DEPTH TIME NODES SCORE PV
1/1 0.2 188 -0.23 d7b6
2/2 0.3 1411 -3.87 c5f8 f7d7
3/5 0.3 2859 -3.85 c5f8 f7d7 c6c5 f5d4 e5d4
4/6 0.4 5974 -3.88 c5f8 f7d7 c6c5 h1g2
5/8 0.5 12116 -3.91 c5f8 f7d7 c6c5 h1g2 d4c3
6/11 0.9 34833 -4.02 c5f8 f7d7 c6c5 f5d4 e5d4 h1g2
7/14 3.4 168849 -1.13 c5f8 f7d7 c6d6 d7c7 f8f5 h1g2 f5h5
8/16 5.3 275740 -1.26 c5f8 f7d7 c6d6 d7c7 f8f5 h1g2 f5h5 g3g4
9/19 14.6 789701 -1.04 c5f8 f7d7 c6d6 d7c7 f8f5 c7b8 h8g7 h1g2
d6d7 g3g4
10/25 71.7 3900347 -0.54 c5f8 f7d7 c6d6 d7c7 f8f5 e2g2 d6d7 c7c8
h8g7 g3g4 f5f1 h2g1 d7f7
So the score drops after 3 seconds.
PK.
>PostModernist doesn't show Qf8 after Nf5, which he ought to investigate.
>
>Will
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