Author: Slater Wold
Date: 23:25:25 03/16/02
This position came up on an ICC game:
[D]r1b2rk1/pp1n1ppp/4pB2/2R1P3/8/3B4/q4PPP/3Q1RK1 b - - 0 17
This is from my log:
White(17): Bf6
time used: 31.43
time limit 14.74 (1:39)
nss depth time score variation (1)
7 0.21 ++ 17. ... Re8!!
7 0.35 -0.87 17. ... Re8 18. Qg4 g6 19. Bb5 Nxc5
20. Bxe8 Bd7 21. Bxd7 Nxd7
7 0.72 ++ 17. ... gxf6!!
7 1.33 -3.42 17. ... Qa3 18. Qg4 g6 19. Rxc8 Rfxc8
20. Be4 Nxf6 21. exf6 Qb3
(4) 7-> 1.39 -3.42 17. ... Qa3 18. Qg4 g6 19. Rxc8 Rfxc8
20. Be4 Nxf6 21. exf6 Qb3
8 1.66 -- 17. ... Qa3
(3) 8 2.00 0.00 17. ... Qa3 18. Bxh7+ Kxh7 19. Qh5+
Kg8 20. Bxg7 Kxg7 21. Qg5+ Kh7 22.
Qh5+ Kg7
8 2.64 ++ 17. ... Re8!!
8 4.02 -0.93 17. ... Re8 18. Qh5 h6 19. Qg4 g6 20.
Rc7 Qd5 21. Qg3 Nxf6 22. exf6
8-> 5.61 -0.93 17. ... Re8 18. Qh5 h6 19. Qg4 g6 20.
Rc7 Qd5 21. Qg3 Nxf6 22. exf6
9 6.35 -- 17. ... Re8
9 16.54 5.92 17. ... Re8 18. Bxh7+ Kh8 19. Qh5 Qe2
20. Qxf7 gxf6 21. Qxe8+ Kxh7 22. Rxc8
Nxe5 23. Qg8+ Kh6 24. Rxa8
9 16.88 ++ 17. ... Qa3!!
time=17.11 cpu=196% mat=-2 n=24143380 fh=94% nps=1411k
ext-> chk=1598422 cap=47309 pp=18507 1rep=176270 mate=14056
sing=10
predicted=16 nodes=24143380 evals=2438674
endgame tablebase-> probes done=0 successful=0
hashing-> trans/ref=28% pawn=99% used=65%
SMP-> split=482 stop=108 data=8/32 cpu=33.65 elap=17.11
I don't think there is a worse move than Qa3. I cringed when I saw this move
played.
Oh well, that's why I am playing there, to catch these little things. So I go
back to my engine, and feed it the position, and let it think for 60 seconds.
Here is the eval:
White(1): setboard r1b2rk1/pp1n1ppp/4pB2/2R1P3/8/3B4/q4PPP/3Q1RK1 b - - 0 17
Black(1): go
clearing hash tables
time surplus 0.00 time limit 1:00 (1:00)
nss depth time score variation (1)
starting thread 1
(2) 7-> 0.25 -7.16 1. ... Nxc5 2. Qg4 g6 3. Bc4 Qc2 4.
Rd1 Qf5
8 0.39 -- 1. ... Nxc5
8 0.73 Mat06 1. ... Nxc5 2. Bxh7+ Kxh7 3. Qh5+ Kg8
4. Qg4 g6 5. Qh4 Qxf2+ 6. Rxf2 Nd7
7. Qh8#
8 1.11 ++ 1. ... gxf6!!
8 2.86 0.00 1. ... gxf6 2. Bxh7+ Kxh7 3. Qh5+ Kg8
4. Qg4+ Kh7 5. Qh5+
8 3.16 ++ 1. ... Re8!!
8 3.98 -0.85 1. ... Re8 2. Bb5 Nxc5 3. Qg4 g6 4.
Bxe8 Nd7 5. Bxd7 Bxd7
(2) 8-> 6.33 -0.85 1. ... Re8 2. Bb5 Nxc5 3. Qg4 g6 4.
Bxe8 Nd7 5. Bxd7 Bxd7
9 7.63 -- 1. ... Re8
9 8.97 4.60 1. ... Re8 2. Bxh7+ Kxh7 3. Qh5+ Kg8
4. Qg5 Nxf6 5. exf6 Qxf2+ 6. Kxf2 g6
7. Rc7 Rd8 8. Re7 a5
9 10.55 ++ 1. ... gxf6!!
9 16.50 1.16 1. ... gxf6 2. Bxh7+ Kh8 3. Qh5 Qe2
4. Qh6 Qd2 5. Qxd2 Nxc5 6. Qh6
9 19.80 ++ 1. ... Nxf6!!
9 21.38 -0.38 1. ... Nxf6 2. exf6 Qb2 3. Bxh7+ Kxh7
4. Qh5+ Kg8 5. fxg7 Qxg7 6. Rg5 f6
7. Rxg7+ Kxg7 8. Rd1 a5 9. g3
(4) 9-> 24.44 -0.38 1. ... Nxf6 2. exf6 Qb2 3. Bxh7+ Kxh7
4. Qh5+ Kg8 5. fxg7 Qxg7 6. Rg5 f6
7. Rxg7+ Kxg7 8. Rd1 a5 9. g3
(3) 10 28.78 -0.37 1. ... Nxf6 2. exf6 Qb2 3. Bxh7+ Kxh7
4. Qh5+ Kg8 5. fxg7 Qxg7 6. Rg5 f6
7. Rxg7+ Kxg7 8. Rd1 a5 9. f4 a4 10.
Kf2
10-> 36.83 -0.37 1. ... Nxf6 2. exf6 Qb2 3. Bxh7+ Kxh7
4. Qh5+ Kg8 5. fxg7 Qxg7 6. Rg5 f6
7. Rxg7+ Kxg7 8. Rd1 a5 9. f4 a4 10.
Kf2
11 51.30 -0.22 1. ... Nxf6 2. exf6 Qb2 3. Bxh7+ Kxh7
4. Qh5+ Kg8 5. fxg7 Qxg7 6. Rg5 f6
7. Rxg7+ Kxg7 8. Qg4+ Kf7 9. Qh5+ Ke7
10. Qc5+ Ke8 11. Rd1 Kf7 12. f4
time=1:00 cpu=234% mat=-2 n=82822082 fh=90% nps=1372k
ext-> chk=3645381 cap=287364 pp=75218 1rep=496025 mate=38058 sing=
25
predicted=0 nodes=82822082 evals=16376870
endgame tablebase-> probes done=0 successful=0
hashing-> trans/ref=33% pawn=28% used=96%
SMP-> split=1927 stop=605 data=7/32 cpu=2:21 elap=1:00
Never even evaluates it. Strange!!
Same version, settings, everything. I know it *probably* has to do with hash
and other in-game conditions. (And yes, positional learning _IS_ disabled.)
But it's *very* hard to diagnose a problem that cannot be reproduced. :(
Anything but Nxf6 here is just wrong. Most programs will evaluate Qa3 (and
other losers) but fail low quickly on them, and move on to Nxf6.
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Last modified: Thu, 15 Apr 21 08:11:13 -0700
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