Author: Dann Corbit
Date: 11:00:11 07/19/99
Go up one level in this thread
You are expecting way too much from chess engines. In fact, for this position,
there is no sure mate within 14 plies. For a chess engine to find such a move
with certainty, it would have to be deep blue or something phenomenal.
Here is the output of Heiner Marxen's excellent chess problem solving engine:
Reading job:
W: Kg2 Qe3 Rc4 Bb2 Nd4 Ng4 Pb3 Pe4 Pf3 Pg3 Ph2 (11)
B: Kg8 Qb7 Rc8 Be7 Nb8 Nd7 Pa6 Pe6 Pf7 Pg7 Ph7 (11)
FEN: 1nr3k1/1q1nbppp/p3p3/8/2RNP1N1/1P2QPP1/1B4KP/8 w - -
analysing (mate in 7 moves):
No solution in 7 moves.
refu 1: Nf6+ gf6 [ 6-]
refu 2: Nh6+ gh6 [ 6-]
refu 3: Rc8:+ Qc8: [ 6-]
refu 4: h3 Qb3: [ 6-]
refu 5: h4 Qe4: [ 6-]
refu 6: f4 Qe4:+ [ 6-]
refu 7: e5 Qd5 [ 6-]
refu 8: b4 Qe4: [ 6-]
refu 9: Ne5 Qe4: [ 6-]
refu 10: Nf2 Qe4: [ 6-]
refu 11: Nb5 Qe4: [ 6-]
refu 12: Nc6 Qc7 [ 6-]
solu 1: Qb3: [ 6+]
refu 13: Nc2 Qe4: [ 6-]
refu 14: Ne6: Qe4: [ 6-]
refu 15: Ne2 Qe4: [ 6-]
refu 16: Nf5 Rc4: [ 6-]
solu 2: Qe4: [ 4+]
solu 3: Qb3: [ 4+]
refu 17: Bc3 Qe4: [ 6-]
refu 18: Ba1 Qe4: [ 6-]
refu 19: Bc1 Qe4: [ 6-]
refu 20: Ba3 Qe4: [ 6-]
refu 21: Rb4 Rc2+ [ 6-]
refu 22: Ra4 Rc2+ [ 6-]
refu 23: Rc5 Qe4: [ 6-]
refu 24: Rc6 Qb3: [ 6-]
refu 25: Rc7 Qc7: [ 6-]
refu 26: Rc3 Qe4: [ 6-]
refu 27: Rc2 Rc2:+ [ 6-]
refu 28: Rc1 Rc2+ [ 6-]
refu 29: Qd3 Qe4: [ 6-]
refu 30: Qc3 Qe4: [ 6-]
refu 31: Qe2 Qe4: [ 6-]
refu 32: Qe1 Qe4: [ 6-]
refu 33: Qf4 Qe4: [ 6-]
refu 34: Qg5 Qc7 [ 6-]
solu 4: Qe4: [ 6+]
solu 5: Qb3: [ 4+]
refu 35: Qh6 Qe4: [ 6-]
refu 36: Qd2 Qb4 [ 6-]
refu 37: Qc1 Qe4: [ 6-]
refu 38: Qf2 Qe4: [ 6-]
refu 39: Qg1 Qb3: [ 6-]
refu 40: Kf2 Qe4: [ 6-]
refu 41: Kg1 Qb3: [ 6-]
refu 42: Kh3 Qd5 [ 6-]
refu 43: Kf1 Qb3: [ 6-]
refu 44: Kh1 Qb3: [ 6-]
Time (user) = 557.00 sec (ca. 9.3 min)
Here is the output from Crafty. It does not find the 'best' move, even after 10
minutes (caveat, both of these runs were made on low priority and during a huge
compile...):
PFGA: EPD record: 1
clearing hash tables
time surplus 0.00 time limit 12:00 (12:00)
s depth time score variation (1)
White(1): exit
6 0.87 0.07 1. Rxc8+ Qxc8 2. Qc3 Qf8 3. Kg1 Nf6
4. Nxf6+ Bxf6 5. Qd3 Qd6
6 1.10 0.11 1. Qc3 Rxc4 2. Qxc4 Nb6 3. Qd3 Qd7
4. Kg1
6 1.66 ++ 1. Nf5!!
6 2.03 1.39 1. Nf5 Nc6 2. Nxg7 Nb6 3. Nh6+ Kf8
4. Rc2
6-> 2.10 1.39 1. Nf5 Nc6 2. Nxg7 Nb6 3. Nh6+ Kf8
4. Rc2
7 3.43 1.76 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Nc6 5. Qf4
7-> 3.74 1.76 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Nc6 5. Qf4
8 6.11 1.64 1. Nf5 Rxc4 2. Nxe7+ Kh8 3. Bxg7+ Kxg7
4. bxc4 Qb2+ 5. Kh3 Qb4 6. Qd4+ f6
7. Nc8
8-> 8.09 1.64 1. Nf5 Rxc4 2. Nxe7+ Kh8 3. Bxg7+ Kxg7
4. bxc4 Qb2+ 5. Kh3 Qb4 6. Qd4+ f6
7. Nc8
9 12.99 1.74 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Nc6 5. Qa3+ Kd8 6. Qd6 Qc7
9-> 16.77 1.74 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Nc6 5. Qa3+ Kd8 6. Qd6 Qc7
10 28.45 1.70 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Qb4 5. Qg5+ Kd6 6. Be5+ Kc6
7. Qf4 Nxe5 8. Nxe5+
10-> 1:50 1.70 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Qb4 5. Qg5+ Kd6 6. Be5+ Kc6
7. Qf4 Nxe5 8. Nxe5+
11 2:20 1.55 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Qb4 5. Qg5+ Ke8 6. Nf6+ Nxf6
7. Bxf6 Nd7 8. Qg8+ Qf8 9. Qg5 Nxf6
10. Qxf6
11-> 3:40 1.55 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Qb4 5. Qg5+ Ke8 6. Nf6+ Nxf6
7. Bxf6 Nd7 8. Qg8+ Qf8 9. Qg5 Nxf6
10. Qxf6
12 4:42 1.58 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Qb4 5. Qg5+ Ke8 6. h4 Qxc4
7. Qh5 Qe2+ 8. Nf2 Nc6 9. Qxh7
12-> 7:05 1.58 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Qb4 5. Qg5+ Ke8 6. h4 Qxc4
7. Qh5 Qe2+ 8. Nf2 Nc6 9. Qxh7
13 10:11 1.58 1. Nf5 Rxc4 2. Nxe7+ Kf8 3. Bxg7+ Kxe7
4. bxc4 Qb4 5. Qg5+ Ke8 6. h4 Qxc4
7. Qh5 Nc6 8. Qxh7 Nd4
time=12:00 cpu=99% mat=0 n=76624316 fh=94% nps=106295
ext-> checks=5118843 recaps=314202 pawns=11854 1rep=326823
thrt:33550
predicted=0 nodes=76624316 evals=8282941
endgame tablebase-> probes done=0 successful=0
If, in fact, the stated move is really the best (quite likely it is) then it is
a very, very difficult position to solve. Any engine that does solve it (with a
corresponding centipawn evaluation to show that it is not an accident) is to be
roundly congratulated.
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Last modified: Thu, 15 Apr 21 08:11:13 -0700
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