Author: Michael Fuhrmann
Date: 16:30:58 01/06/02
This position arose in a game on my comp between Crafty 18.12 and Yace 99.56:
[D] 8/r7/P3Q3/4p1k1/3bKp2/8/8/8 b - - 0 99
Crafty played Kh4. It was the losing move. Log file of game shows Crafty thinks
this move draws.
White(99): time 31896
time remaining: 5:18 (crafty).
White(99): otim 36390
time remaining: 6:03 (opponent).
White(99): Qe6
time used: 17.22
time surplus 0.00 time limit 14.49 (1:34)
nss depth time score variation (1)
10-> 1.05 0.00 99. ... Kh4 100. Kf3 Kh5 101. Qf5+
Kh6 102. Qf6+ Kh7 103. Qf5+ Kh6
11 1.85 0.00 99. ... Kh4 100. Kf3 Kh5 101. Qf5+
Kh6 102. Qf6+ Kh7 103. Qf5+ Kh6
11-> 2.46 0.00 99. ... Kh4 100. Kf3 Kh5 101. Qf5+
Kh6 102. Qf6+ Kh7 103. Qf5+ Kh6
12 5.03 0.00 99. ... Kh4 100. Kf3 Kh5 101. Qf5+
Kh6 102. Qf6+ Kh7 103. Qf5+ Kh6
12-> 5.73 0.00 99. ... Kh4 100. Kf3 Kh5 101. Qf5+
Kh6 102. Qf6+ Kh7 103. Qf5+ Kh6
13 12.26 0.00 99. ... Kh4 100. Kf3 Kh5 101. Qf5+
Kh6 102. Qf6+ Kh7 103. Qf5+ Kh6
13-> 13.99 0.00 99. ... Kh4 100. Kf3 Kh5 101. Qf5+
Kh6 102. Qf6+ Kh7 103. Qf5+ Kh6
time=15.54 cpu=98% mat=0 n=3153431 fh=91% nps=202k
ext-> chk=277624 cap=399 pp=20672 1rep=9469 mate=637
predicted=11 nodes=3153431 evals=572157
endgame tablebase-> probes done=0 successful=0
hashing-> trans/ref=60% pawn=99% used=39%
Black(99): Kh4
time used: 15.54
I let Crafty analyze this position after the game. And was surprised that at no
time did Crafty want to play Kh4, the move it played in the game. Here's log of
analysis:
end-game phase
clearing hash tables
time surplus 0.00 time limit 30.00 (3:30)
nss depth time score variation (1)
7 0.96 -0.26 1. ... Rc7 2. Qf5+ Kh4 3. Qf6+ Kg3
4. Qg5+ Kf2 5. Qh4+ Kf1 6. Qh3+ Ke2
7. Qf3+ Kd2
7-> 1.24 -0.26 1. ... Rc7 2. Qf5+ Kh4 3. Qf6+ Kg3
4. Qg5+ Kf2 5. Qh4+ Kf1 6. Qh3+ Ke2
7. Qf3+ Kd2
8 2.09 -0.22 1. ... Rc7 2. Qg8+ Kf6 3. Qd8+ Re7
4. Qh8+ Kg6 5. Qg8+ Rg7 6. Qe6+ Kg5
7. Qf5+ Kh4 8. Kd5
8-> 2.62 -0.22 1. ... Rc7 2. Qg8+ Kf6 3. Qd8+ Re7
4. Qh8+ Kg6 5. Qg8+ Rg7 6. Qe6+ Kg5
7. Qf5+ Kh4 8. Kd5
9 3.34 -0.22 1. ... Rc7 2. Qg8+ Kf6 3. Qd8+ Re7
4. Qd6+ Kf7 5. Kf5 Ra7 6. Qg6+ Ke7
7. Qe6+ Kd8 8. Ke4
9-> 3.98 -0.22 1. ... Rc7 2. Qg8+ Kf6 3. Qd8+ Re7
4. Qd6+ Kf7 5. Kf5 Ra7 6. Qg6+ Ke7
7. Qe6+ Kd8 8. Ke4
10 7.47 -0.12 1. ... Rc7 2. Qg8+ Kf6 3. Qh8+ Ke6
4. Qe8+ Kd6 5. Qf8+ Re7 6. Qb8+ Kc6
7. Qa8+ Kb5 8. Qd5+ Bc5 9. Qd3+ Kc6
<HT>
10-> 9.56 -0.12 1. ... Rc7 2. Qg8+ Kf6 3. Qh8+ Ke6
4. Qe8+ Kd6 5. Qf8+ Re7 6. Qb8+ Kc6
7. Qa8+ Kb5 8. Qd5+ Bc5 9. Qd3+ Kc6
<HT>
11 14.08 -0.09 1. ... Rc7 2. Qg8+ Kf6 3. Qh8+ Ke6
4. Qe8+ Kd6 5. Qf8+ Re7 6. Qh6+ Kc7
7. Qf6 Rd7 8. a7 Kb7 9. Qe6 Rd8
11-> 15.47 -0.09 1. ... Rc7 2. Qg8+ Kf6 3. Qh8+ Ke6
4. Qe8+ Kd6 5. Qf8+ Re7 6. Qh6+ Kc7
7. Qf6 Rd7 8. a7 Kb7 9. Qe6 Rd8
12 33.35 0.00 1. ... Rc7 2. Qd6 Ra7 3. Qe6
Black(0): quit
execution complete.
So my question is, why did crafty play Kh4 in the game (thinking it draws), when
during analysis it understands that Rc7 is much better?
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