Author: Will Singleton
Date: 15:40:50 04/16/03
Go up one level in this thread
On April 16, 2003 at 14:37:18, Dieter Buerssner wrote:
>On April 15, 2003 at 17:23:09, Will Singleton wrote:
>
>>r1br2k1/p1q2ppp/2n2n2/2B5/P1BNp3/1QP1P3/5PPP/R4RK1 b - -
>>
>>Some programs never show an elevated score, others show +2 or so before figuring
>>it out. It has to do with a piece that is guarding a pinned piece at the end of
>>the pv. Ruffian and Yace 99.5 exhibit the problem, while Tao doesn't. I'm
>>wondering if this problem is due to a lack of extensions in the pv, or a qsearch
>>artifact, or something else.
>>10 216 736 3122242 Ne5 Qb4 Nxc4 Nb5 Qc6 Qxc4 Rd5 Rd1 Rxc5 Rd8 Ne8
>>
>>However, at the end of that pv, you get the following position:
>
>This PV is 11 ply deep, probably no extensions (?). I just tried Yace, and it
>neede 11 ply, to get a drawish score. Disabling all pruning in qsearch (and
>using even some very limited extensions in qsearch) did not make a difference.
>But it is probably a bit more complicated as that. I also should check
>carefully, if really all pruning in qsearch was disabled. At least the line QxR
>QxQ RxN+ Qf8 RxQ KxR should be seen in qsearch here.
Yes, i forgot about that line originally, but it doesn't change the problem. In
my pv above, I only had the one check extension.
>
>Can you show some analysis of programs, that never show a higher score of black?
>
>Regards,
>Dieter
Knightdreamer, for example:
7 -39 28 255363 c6e5 b3b4 a7a5 c5b6 c7d6 b4b3 a8b8 f2f4
b8b6 f4e5 b6b3 e5d6 b3c3 (908.8k)
8 -38 68 644000 c6e5 b3b4 a7a5 c5b6 c7d6 b6a5 d6b4 c3b4
a8a5 b4a5 e5c4 (937.4k)
9 -69 229 2191343 c6e5 b3b4 f6g4 g2g3 a8b8 d4b5 e5f3 g1h1
c7e5 c5d4 e5h5 (954.4k)
9 -58 287 2779072 ++ c6a5 (966.6k)
9 -42 303 2946749 ++ c6a5 (972.2k)
9 -10 323 3145081 ++ c6a5 (972.5k)
9 9 353 3452464 c6a5 b3b4 a5c4 b4c4 d8d5 d4b3 d5h5 f2f4
e4f3 g2g3 (977.8k)
10 10 818 7902106 c6a5 b3b4 a5c4 d4b5 c7c6 b4c4 f6d7 f1d1
c8b7 b5d6 d7c5 d6b7 d8d1 a1d1 c6a4
(965.2k)
11 10 2032 19577042 c6a5 b3b4 a5c4 d4b5 c7c6 b4c4 f6d7 f1d1
c8b7 b5d6 d7c5 d6b7 d8d1 a1d1 c6a4
(963.1k)
It gets to -.69, but that's purely positional, no material loss.
Will
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