In the latest CCRL Division 9, Myrddin reached this position against Roc and played the key move. I'm a total patzer, so I have no idea why it even works. If somebody could enlighten me (after you find it), I'd appreciate it!
[d]1r1qbk2/5pbQ/p2p4/n1pPpBP1/1rP1Pn2/4NK2/P2N4/R1B3R1 w - - 21 45
jm
A good test for humans (and maybe engines under 2500?)
Moderator: Ras
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JVMerlino
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carldaman
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Re: A good test for humans (and maybe engines under 2500?)
I spent about 5 min studying the position, and it increasingly looked like a white Knight belonged on f5 since it would be extremely difficult to defend against the threat on g7.
So I had to pick what looked like the best square to move the f5 bishop to and settled on c8.
I then double-checked with the private engine CyberNezh (roughly 2900 Elo) and it instantly wanted to play Bf5-c8!
Is that the absolute best move, though?
So I had to pick what looked like the best square to move the f5 bishop to and settled on c8.
I then double-checked with the private engine CyberNezh (roughly 2900 Elo) and it instantly wanted to play Bf5-c8!
Is that the absolute best move, though?
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JVMerlino
- Posts: 1404
- Joined: Wed Mar 08, 2006 10:15 pm
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Re: A good test for humans (and maybe engines under 2500?)
Bc8 is indeed the move! I have no idea why, but I did confirm it with several strong engines, including SF.carldaman wrote: ↑Tue Sep 02, 2025 6:20 am I spent about 5 min studying the position, and it increasingly looked like a white Knight belonged on f5 since it would be extremely difficult to defend against the threat on g7.
So I had to pick what looked like the best square to move the f5 bishop to and settled on c8.
I then double-checked with the private engine CyberNezh (roughly 2900 Elo) and it instantly wanted to play Bf5-c8!
Is that the absolute best move, though?
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carldaman
- Posts: 2287
- Joined: Sat Jun 02, 2012 2:13 am
Re: A good test for humans (and maybe engines under 2500?)
It's a clearance sac, to allow the crushing Ne3-f5, which should win whether the Bishop is taken or not. Other light-squared Bishop moves don't look as good since they get in the way of White's threats.
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Dann Corbit
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Re: A good test for humans (and maybe engines under 2500?)
Code: Select all
Analysis of G:\best.epd
9/2/2025 9:31:36 PM Level: 180 Seconds
Analyzing engine: Crystal-native
1 Bc8;
Searching move: Bf5-c8
Best move (Crystal-native): Bf5-c8
Identical moves! Found in: 00:00
Found 747 WDL and 741 DTZ tablebase files (up to 7-man).
Available processors: 0-31
Using 31 threads
info string NNUE evaluation using nn-1c0000000000.nnue (133MiB, (22528, 3072, 15, 32, 1))
info string NNUE evaluation using nn-37f18f62d772.nnue (6MiB, (22528, 128, 15, 32, 1))
2/5 00:00 56k 5,108k +2.40 a3 Rb3
3/7 00:00 136k 11,325k +2.55 Rg4 Ba4 Ba3
4/8 00:00 154k 12,801k +2.65 Rg4 Ba4 Ba3 Rb2 Bxb2 Rxb2
5/11 00:00 225k 17,298k +2.65 Rg4 Ba4 Ba3 Rb2 Bxb2 Rxb2 Ndf1 Bc2
6/14 00:00 623k 38,962k +2.80 Bh3 Nxh3 Qxh3 Bd7 Qh7 Ra4 Kf2 Qe7
7/17 00:00 914k 45,675k +2.90 Bh3 Nxh3 Qxh3 Ra4 Qh7 Bd7 Rg3 Rbb4 Kg2
8/22 00:00 2,289k 52,026k +2.20 Kf2 R8b7 Kf3 Ra4 Bc8 Qxc8
9/22 00:00 4,027k 54,420k +3.00 Bc8 Nc6 dxc6 Qxc8 Nf5 Ne6 c7 R8b6
10/28 00:00 5,445k 54,445k +3.35 Bc8 f5 Nxf5 R8b7 Be6 Nxe6 dxe6 Nc6 a3 R4b6 Kg2
11/30 00:00 9,610k 51,947k +4.05 Bc8 f6 Nf5 R8b7 Be6 Nxe6 dxe6 fxg5 Nb3 Nxb3
12/30 00:00 14,089k 47,278k +4.30 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 Kf2 Kd7 a3 Rbb6 a4 Kc7 a5 Rb4
13/29 00:00 14,906k 46,873k +4.30 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 Rf1 Kd7 Ke2 Qe7 Qf6 Rcb6
14/38 00:00 17,039k 45,436k +4.30 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 Kg3 Kd7 Rb1 Kc7 Rb3 Qd7 Rf3 Ra4 a3 Rb6 Qf8 Rb8
15/41 00:00 23,318k 41,939k +4.45 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 Nf1 Rcb6 Qf6+
16/39 00:00 28,624k 40,259k +4.45 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 g6 Ke6 Ke3
17/48 00:03 143,878k 36,416k +5.05 Bc8 Rb3 axb3 Nxb3 Nxb3 Rxb3 Bf5 Qc7 Qh2 a5 Ra3 a4 Rxb3 axb3 Qb2 Qb7 Bd2
18/48 00:04 147,194k 36,525k +5.10 Bc8 Rb3 axb3 Nxb3 Nxb3 Rxb3 Bf5 Qc7 Qh2 a5 Ra3 a4 Rxb3 axb3 Qb2 Ba4 Bd2 Ng6 Qa1 Qa7 Rh1 Qa6 Qc3 Ne7 Kf2 Qb7 Qa5 Be8 Bh7 Bh8
19/37 00:04 181,387k 36,445k +5.15 Bc8 Rb3 axb3 Nxb3 Nxb3 Rxb3 Bf5 Qc7 Qh2 a5 Ra3 a4 Rxb3 axb3 Qb2 Ba4 Bd2 Ng6 Qa1 Qa7 Rh1 Qa6 Qc3 Nf4 Qa5
20/44 00:05 209,621k 36,260k +5.20 Bc8 Rb3 axb3 Nxb3 Nxb3 Rxb3 Bf5 Qc7 Qh2 a5 Ra3 a4 Rxb3 axb3 Qb2 Qb8 Bd2 Qb6 Rh1 Ba4 Bc3 Qa6 Qa1 Nd3 Bd2 Nf4 Qc3 Ke7 Qa5 Qxa5 Bxa5 b2
21/45 00:06 228,025k 36,206k +5.25 Bc8 Rb3 axb3 Nxb3 Nxb3 Rxb3 Bf5 a5 Ra3 Qb6 Rxb3 Qxb3 Qh2 a4 Qc2 Qb6 Rh1 Qa5 Bd2 Qb6 Qa2 Qa6 Qb1 Qa7 Bc1 Ng6 Rg1
22/55 00:10 364,003k 34,697k +5.40 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Bf5 a5 Ra3 Rxa3 Bxa3 Qb6 Bc1 Qb3 Qh2 a4 Qb2 Qb4 Qxb4 cxb4 Nc2 Nd3 Nxb4 Nxb4 Ba3 Nc2 Bxd6+ Kg8 Rc1 a3 Rxc2 Ba4 Bxa3 Bf8 Rh2 Bxa3 Ke2 Bc2 Rh3
23/45 00:13 481,116k 34,821k +5.45 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Bf5 Nd3 Bd2 Rb2 Qh2 Qb6 Ra3 Nf4 Rga1 Qd8 Kg4 f6 g6 Nxg6 Rxa6 Nf4 Ra8 Rb8 Rxb8 Qxb8
24/47 00:16 578,423k 34,694k +5.50 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Bf5 a5 Ra3 Rxa3 Bxa3 Qb6 Bc1 Qb3 Qh2 a4 Qc2 Qb8 Qb2 Qa7 Qb1 Kg8 Rh1 Ng6
25/51 00:22 790,370k 34,367k +5.60 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Bf5 a5 Ra3 Rxa3 Bxa3 Qb8 Bc1 Qb7 Qh2 Nd3 Qc2 Nxc1 Qxc1 a4 Qc2 Qb4 Ra1 Qa5 Rb1 Qd8 Qh2
26/48 00:25 864,417k 34,298k +5.65 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Bf5 a5 Ra3 Rxa3 Bxa3 Qb6 Bc1 Qb3 Qh2 Ba4 Qb2 Qb4 Rh1 Nd3 Qd2 Nf4 Qxb4 axb4 Bd2 Nd3 Ra1 b3 Rb1 b2
27/65 00:35 1,184,617k 33,577k +5.65 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Bf5 a5 Ra3 Qb6 Rxb3 Qxb3 Qh2 Qb4 Qa2 a4 Qc2 Qa5 Rh1 Kg8 Qb2 Qb4 Qd2 Qb6 Qa2 Qa5 Qb1 Qb4 Qxb4 cxb4 Nc2 Nd3 Bd2 b3 Na3 Bf8 g6 Be7
28/67 01:25 2,733,902k 32,112k +6.05 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Bf5 a5 Ra3 Qb6 Rxb3 Qxb3 Qh2 Qb4 Qa2 Qb6 Qb2 Qa7 Qb1 a4 Rh1 Qc7 Bd2 Qd8 Ng4 a3 Qa2 Qxg5 Qxa3 Qd8 Be3 Qb6 Qa2 Qd8 Bxf4 exf4 Qh2 Qb8 Qxf4 Qb3+ Kg2 Ke7 e5 dxe5 Qg5+ Kf8 Rh7 Bf6
29/61 02:16 4,184,790k 30,742k +6.20 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Bf5 a5 Ra3 Rxa3 Bxa3 Qb8 Bc1 Qb3 Qh2 Ba4 Qb2 Qb4 Qxb4 axb4 Bd2 f6 g6 Be8 Rh1 Nxg6 Be6 Ne7 Kf2 Ba4 Ra1 Bh6 Nf1 Bg5
9/2/2025 9:34:39 PM, Time for this analysis: 00:03:00, Rated time: 00:00
1 of 1 matching moves
9/2/2025 9:34:39 PM, Total time: 12:03:03 AM
Rated time: 00:00 = 0 Seconds
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Analysis of G:\best.epd
9/2/2025 9:31:36 PM Level: 60 Seconds
Analyzing engine: Lc0-0.32.0
1 Bc8;
Searching move: Bf5-c8
Best move (Lc0-0.32.0): Bf5-c8
Identical moves! Found in: 00:00
2/3 00:00 3 81 +3.23 Bh3 f5 Bxf5
2/4 00:00 10 156 +2.71 Bh3 f5 Bxf5 Bh5+
3/4 00:00 25 221 +9.60 Bc8 f6 Nf5 Bh5+
3/5 00:00 31 244 +10.51 Bc8 f6 Be6 Bh5+ Kf2
3/6 00:00 38 263 +12.68 Bc8 f6 Be6 Bh5+ Kf2
4/7 00:00 58 331 +15.47 Bc8 f6 Be6 Bh5+ Kf2 Bf7
4/8 00:00 84 388 +15.35 Bc8 f6 Be6 Bh5+ Kf2 Bf7 Bxf7
4/9 00:00 132 501 +14.89 Bc8 f5 Nxf5 Bh5+ Kf2 R4b7 Be6 Ke8
5/10 00:00 189 645 +9.69 Bc8 f5 Nxf5 Bh5+ Kf2 R4b7 Be6 Ke8
6/11 00:00 435 1k +9.71 Bc8 f6 Be6 Bh5+ Kf2 Bf7 Bxf7 Kxf7 Nf5 Qh8
6/12 00:00 708 1k +10.38 Bc8 Nc6 dxc6 Qxc8 Nf5 Ne6 Kf2 Bxc6 Rh1 Ke8 Nxd6+ Ke7
7/13 00:00 879 1k +8.74 Bc8 Nc6 dxc6 Qxc8 Nf5 Ne6 Kf2 Bxc6 Rh1 Ke8 Nxd6+ Ke7
7/14 00:00 1k 2k +8.03 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 c7 Qd7 Rh1 Qa4
7/15 00:00 1k 2k +7.22 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qf8 Qf6+
8/16 00:00 1k 2k +6.42 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7
8/17 00:00 2k 2k +5.85 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7
8/18 00:01 2k 2k +8.91 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7
8/19 00:01 2k 2k +8.77 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+
8/20 00:01 3k 2k +7.93 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qxd6 Rb7 Qxe5+
8/21 00:01 3k 2k +7.69 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qf6 Rc7 Ba3 Qg6
9/21 00:01 3k 2k +7.30 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qf6 Rc7 Ba3 Qg6 Nxd6+
9/22 00:01 3k 2k +7.31 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qf6 Rc7 Ba3 Qg6 Nxd6+ Kd7
9/23 00:01 4k 2k +6.96 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qf6 Rc7 Ba3 Qg6 Nxd6+ Kd7 Qxg6
10/23 00:02 4k 2k +6.96 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qf6 Rc7 Ba3 Qg6 Nxd6+ Kd7 Qxg6
10/24 00:02 6k 2k +6.73 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qf6 Rc7 Ba3 Qg6 Nxd6+ Kd7 Qxg6 fxg6
10/25 00:03 7k 2k +6.58 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qf6 Rc7 Qxd6 Qg6 Qxe5+ Kd8 Ba3
11/25 00:03 8k 2k +6.50 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Re8 Rxe7+ Rxe7 g6
11/26 00:03 8k 2k +6.40 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Re8 Rxe7+ Rxe7 g6
11/27 00:05 12k 2k +6.23 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Re8 Rxe7+ Rxe7 g6 Rb8 Rb1
11/28 00:05 13k 2k +6.14 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Re8 Rxe7+ Rxe7 g6 Rb8 Rb1
12/29 00:07 18k 2k +5.98 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qxd6 Qf8 Qxe5+ Kd7 Ba3 Re8 Qf4 Rb6 Rd1 Qh8 Bxc5
12/30 00:07 18k 2k +6.16 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qxd6 Qf8 Qxe5+ Kd7 Ba3 Re8 Qf4 Rb6 Rd1 Qh8 Bxc5
11/30 00:07 18k 2k +6.16 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qxd6 Qf8 Qxe5+ Kd7 Ba3 Re8 Qf4 Rb6 Rd1 Qh8 Bxc5
12/30 00:07 19k 2k +6.19 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qxd6 Qf8 Qxe5+ Kd7 Ba3 Re8 Qf4 Rb6 Rd1 Qh8 Bxc5
12/31 00:09 24k 2k +6.21 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qxd6 Qf8 Qxe5+ Kd7 Ba3 Re8 Qf4 Rb6 Rd1 Qh8 Bxc5
12/32 00:10 25k 2k +6.27 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh6+ Ke8 Qxd6 Qf8 Qxe5+ Kd7 Ba3 Re8 Qf4 Rb6 Rd1 Qh8 Bxc5
12/33 00:13 35k 3k +6.28 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh4 Qg6 Kf2 Bxe4 Qh8+ Qg8 Qh6+ Ke8 Nxe4 Qg6 Nf6+ Kd8 Qf8+ Kc7 Qxd6+ Kb7 Qxe5 Rc6 Bf4
13/33 00:15 39k 3k +6.35 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh4 Qg6 Kf2 Bxe4 Qh8+ Qg8 Qh6+ Ke8 Nxe4 Qg6 Nf6+ Kd8 Qf8+ Kc7 Qxd6+ Kb7 Qxe5 Rc6 Bf4
12/33 00:16 43k 3k +6.58 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh4 Qg6 Kf2 Bxe4 Qh8+ Qg8 Qh6+ Ke8 Nxe4 Qg6 Nf6+ Kd8 Qf8+ Kc7 Qxd6+ Kb7 Qxe5 Rc6 Bf4
13/33 00:16 43k 3k +6.57 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh4 Qg6 Kf2 Bxe4 Qh8+ Qg8 Qh6+ Ke8 Nxe4 Qg6 Nf6+ Kd8 Qf8+ Kc7 Qxd6+ Kb7 Qxe5 Rc6 Bf4
13/33 00:22 57k 3k +6.63 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh4 Qg6 Kf2 Bxe4 Qh8+ Qg8 Qh6+ Ke8 Nxe4 Qg6 Nf6+ Kd8 Qf8+ Kc7 Qxd6+ Kb7 Qxe5 Rc6 Bf4
13/34 00:25 66k 3k +6.74 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh4 Qg6 Kf2 Bxe4 Qh8+ Qg8 Qh6+ Ke8 Nxe4 Qg6 Nf6+ Kd8 Qf8+ Kc7 Qxd6+ Kb7 Qxe5 Rc6 Bf4 Ka7
13/34 00:30 79k 3k +6.51 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg5+ Rxg5 Qxg5 Nf5 Bxc6 Qh8+ Qg8 Qh4 Qg6 Kf2 Bd7 Qe7+ Kg8 Qxd7 Qe6 Qa7 Rcb8 Ba3 R4b7 Qxa6 d5 Rg1+ Kh8
13/34 00:35 93k 3k +6.48 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Re8 Rxe7+ Rxe7 Rh1 Bd7
14/34 00:36 95k 3k +6.47 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Qxh7 Qxh7+ Bd7 Rb1 Rh3 Rb7+
14/35 00:37 99k 3k +6.47 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Qxh7 Qxh7+ Bd7 Rb1 Rh3 Rb7+
14/35 00:57 161k 3k +6.61 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Qxh7 Qxh7+ Bd7 Rb1 Rh3 Rb7+
14/36 00:59 168k 3k +6.61 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Qxh7 Qxh7+ Bd7 Rb1 Rh3 Rb7+ Kxb7
14/36 01:04 181k 3k +6.63 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Qxh7 Qxh7+ Bd7 Rb1 Rh3 Rb7+ Kxb7
14/36 01:09 195k 3k +6.61 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Re8 Rxe7+ Rxe7 Rh1 Bd7 Qf6 Bg4+
15/36 01:13 204k 3k +6.61 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Re8 Rxe7+ Rxe7 Rh1 Bd7 Qf6 Bg4+
15/36 01:18 217k 3k +6.59 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Rxa3+ Ke2 Re8 Rxe7+ Rxe7 Rh1 Bd7 Qf6 Bg4+
15/36 01:23 231k 3k +6.60 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Ba3 Ra4 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Bb2 Rb8 Rah1 Rxb2 R1h7 Ra3+ Kg4
15/36 01:28 245k 3k +6.66 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Re8 Rxe7+ Rxe7 g6 Rb8 Rb1 Rg8
15/36 01:33 259k 3k +6.71 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 R1h7 Qxf5+ exf5
15/36 01:38 273k 3k +6.74 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 g6 Kc7 R1h7
15/36 01:43 287k 3k +6.77 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 g6 Kc7 R1h7
15/36 01:48 301k 3k +6.81 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 R1h7 Qxf5+ exf5 Rxh7
15/36 01:53 315k 3k +6.81 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Qxh7 Qxh7+ Bd7 g6 Rbb8 g7 Rg8 Rb1 Be6
15/36 01:58 329k 3k +6.84 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Qxh7 Qxh7+ Bd7 g6 Rbb8 g7 Rg8 Rb1 Be6
15/36 02:03 343k 3k +6.88 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kc7 Rh7 Qxh7 Qxh7+ Bd7 Nb3 Rbb8 Nxc5 dxc5 Qe7 Rf8+
15/36 02:08 358k 3k +6.90 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 R1h7 Qxf5+ exf5 Rxh7 Rxh7
15/36 02:13 372k 3k +6.92 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 R1h7 Qxf5+ exf5 Rxh7 Rxh7
15/36 02:18 385k 3k +6.94 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 g6 Kc7 R1h7 Kb8 Rxd7
15/36 02:48 471k 3k +7.01 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 g6 Kc7 R1h7 Kb8 Rxd7
16/36 02:53 484k 3k +7.04 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Kd7 Qxf7+ Qe7 Qf5+ Kd8 Rh8+ Be8 Ba3 Rb7 Rah1 Qd7 g6 Kc7 R1h7 Kb8 Rxd7
9/2/2025 9:37:44 PM, Time for this analysis: 00:03:00, Rated time: 00:00
1 of 1 matching moves
9/2/2025 9:37:45 PM, Total time: 12:06:09 AM
Rated time: 00:00 = 0 Seconds
--------------------------------------------------------------------------------
Analysis of G:\best.epd
9/2/2025 9:31:36 PM Level: 60 Seconds
Analyzing engine: Stockfish-x64-avx2
1 Bc8;
Searching move: Bf5-c8
Best move (Stockfish-x64-avx2): Bf5-c8
Identical moves! Found in: 00:00
Found 747 WDL and 741 DTZ tablebase files (up to 7-man).
Available processors: 0-31
Using 31 threads
NNUE evaluation using nn-1c0000000000.nnue (133MiB, (22528, 3072, 15, 32, 1))
NNUE evaluation using nn-37f18f62d772.nnue (6MiB, (22528, 128, 15, 32, 1))
2/3 00:00 5k 2,540k +3.58 Rg3
3/7 00:00 6k 3,087k +3.23 Rg3 f6 a3
4/5 00:00 8k 3,866k +3.25 Rg3 Ng6 Rg4 Nf4
5/7 00:00 19k 6,352k +2.97 Rg3 Ra4
6/8 00:00 20k 6,674k +2.92 Bh3 Nxh3 Qxh3
7/9 00:00 22k 7,334k +3.14 Rg4 Ng6 Kf2
8/9 00:00 25k 6,239k +3.22 Bh3 Nxh3 Qxh3 Ba4 Qh7 Bd7
9/14 00:00 39k 9,629k +2.96 Bh3 Nxh3 Qxh3 Ba4 Qh7 Bd7 Ke2 Bc8 Kf2
10/18 00:00 223k 20,311k +3.05 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3
11/22 00:00 347k 23,107k +3.46 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Bf5 Qb8 Bd2 Rd3 Rab1 Qc7 Rb2 Qd8 Be1 Rxe3+ Kxe3 Bd7
12/19 00:00 433k 24,037k +3.19 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Bf5 Qb8 Bd2 Rd3 Rgb1
13/30 00:00 800k 24,248k +3.30 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Ra3 Qb6 Rxb3 Qxb3 Qh2 a5
14/30 00:00 1,741k 23,845k +3.52 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Ra3 Qb6 Rxb3 Qxb3 Bf5 Qa2 Re1 a5 Rh1 Qe2+ Kg3 a4 Bg4
15/24 00:00 2,062k 23,972k +3.67 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Ra3 Rxe3+ Bxe3 Qxc8 Rb3 Ba4 Rb6 Qd8 Rxa6 Bb3 Bxf4 exf4 Qf5
16/41 00:00 4,840k 24,445k +3.86 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Ra3 Rxe3+ Bxe3 Qxc8 Rb3 Qd8 Qh2 Bd7 Bxf4 exf4 Qxf4 Be5 Qh4 Qa5 g6 Qd2
17/29 00:00 6,143k 24,379k +3.99 Bc8 Nb3 Nxb3 Rxb3 axb3 Rxb3 Ra3 Qb6 Rxb3 Qxb3 Qh2 Ba4 Bf5 a5 Rh1 Ke8 Qd2 Ke7 Bb2
18/39 00:00 9,690k 25,703k +4.06 Bc8 Nb3 axb3 Rxb3 Nxb3 Rxb3 Ra3 Qb6 Rxb3 Qxb3 Qh2 Ba4 Bd2 Qb2 Bf5 Qa2 Rh1 Qb3 Ba5 Ke7 Qd2 Qb8 Bc3 Kf8 Qh2 Qd8 Qh7 Qb6 g6 Be8 gxf7 Bxf7 Qh4 Bh5+ Kf2 Kg8 Be6+ Kh7
19/41 00:00 16,910k 26,258k +4.06 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 a3 Rbb6 Ke2 Kd7 Rf1 Kc7
20/57 00:01 26,018k 25,888k +4.24 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 g6 Ke6 Qh8 fxg6 Qh3+ Kf7 Ke2 Qd7 Qh4 Kg8 Rh1 Qg7 Rb1 g5 Qg3 Rxb1 Nxb1
21/50 00:01 49,030k 24,964k +4.43 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 g6 Ke6 Qh8 fxg6 Qh3+ Kf7 Ke2 Rc7
22/53 00:03 95,286k 23,929k +4.55 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qe8 Rh7 Kd7 Qf6 Ba4 Ba3 Rb7 Rxf7+
23/57 00:08 210,108k 23,613k +4.93 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Qd8 Qxf7+ Qd7 Qxd7+ Bxd7 Rxb4 cxb4 Bb2 a5 g6
24/54 00:09 235,649k 23,584k +4.93 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Ba3 Rb6 Rah1 Qd8 Qxf7+ Bd7 Rg1
25/71 00:17 428,323k 23,834k +5.16 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Qd8 Qxf7+ Bd7 Rh7 Rb7
26/62 00:22 544,444k 24,010k +5.27 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Kb7 Rxb4+ cxb4 c5 Bb5 Nb3 Qe8
27/70 00:26 635,482k 24,017k +5.28 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Qd8 Qxf7+ Bd7 Rh7 Qf8 Rxb4 cxb4 g6 Kc6 Qxf8 Rxf8+ Rf7 Rg8 g7 Be8 Rb7
28/63 00:36 886,367k 23,996k +5.41 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Qd8 Qxf7+ Bd7 Rh7 Qf8 Rxb4 cxb4 g6 Qd8
29/72 00:41 996,768k 24,053k +5.45 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Qd8 Qxf7+ Bd7 Rh7 Qf8 g6 Kc6 Rxb4 Be6
30/85 00:56 1,370,505k 24,187k +5.55 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Kb7 Rxb4+ cxb4 c5 Qd8 Nc4 dxc5 Qxd8 Rxd8 a4
31/60 01:03 1,519,659k 24,048k +5.51 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Rcb8 Ba3 Be8 Bxb4 Rxb4 Qf6+ Kd7 Qxd8+ Kxd8 Rab1 Ke7 Rxb4 cxb4 Rh7 Kf8 Ke3 Kg8 Rh1 Kf8 Rh8+ Ke7
32/79 01:15 1,840,237k 24,269k +5.58 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Rxc6 g6 Ke6 Qh7 fxg6 Qh3+ Kf7 Ke2 Qe7 Rh1 Qg5 Nf3 Qh5 Qg2 Bd7 Rxh5 gxh5 Qg5 Bg4 Kd3 Rcb6 Qd8 Bxf3 Qd7+ Kg8 Qe6+ Kg7 Bh6+ Kh7
33/78 01:35 2,338,442k 24,598k +5.71 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Qd8 Qxf7+ Qd7 Rh7 Qxf7+ Rxf7+ Kb8 Rxb4+ cxb4 g6 Be8 Rf6 Rd8
34/79 01:47 2,655,103k 24,683k +5.75 Bc8 Nc6 dxc6 Rxc8 Nf5 Ne6 Nxg7 Nxg7 Qh8+ Ke7 Qxg7 Bxc6 Rh1 Qg8 Qf6+ Kd7 Rh6 Kc7 Rb1 Qd8 Qxf7+ Bd7 Rh7 Qf8 Rxb4 cxb4 g6 Kc6 Qxf8 Rxf8+ Rf7 Rd8 g7 Be6 Re7 Rd7 Rxe6 Rf7+ Ke3 Rxg7 Bb2
9/2/2025 9:47:07 PM, Time for this analysis: 00:03:00, Rated time: 00:00
1 of 1 matching moves
9/2/2025 9:47:08 PM, Total time: 12:15:32 AM
Rated time: 00:00 = 0 Seconds
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.
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peter
- Posts: 3420
- Joined: Sat Feb 16, 2008 7:38 am
- Full name: Peter Martan
Re: A good test for humans (and maybe engines under 2500?)
After a little Forward- Backward of the with empty hash started line of 1...Bc8, then changed to MultiPV=10- mode (the 11th was the first one not clearly in +-:
Depth 25 with 30 threads of 16x3.5GHz CPU, 8G hash, regards
Code: Select all
1r1qbk2/5pbQ/p2p4/n1pPpBP1/1rP1Pn2/4NK2/P2N4/R1B3R1 w - - 0 1
Analysis by Stockfish dev-20250809-7a07ac0e:
1. +- (5.82): 45.Lc8! f5 46.Sxf5 T8b7 47.Le6 Lh5+ 48.Kf2 Sxe6 49.dxe6 Sc6 50.Dxh5 Sd4 51.Sf3 Sxe6 52.g6 Df6 53.Kg3 Txc4 54.Sg5 Ke8 55.Sh7 Dd8 56.Lg5 Sxg5 57.Dxg5 Txe4 58.Sxg7+ Txg7 59.Sf6+ Kf8
2. +- (3.92): 45.Kf2 Sd3+ 46.Kf3 T4b7 47.Tg3 Sf4 48.Kf2 Tc7 49.Lh3 f5 50.exf5 Tb4 51.Lf1 Sxc4 52.Lxc4 Lb5 53.Lxb5 axb5 54.a3 Td4 55.Sdf1 e4
3. +- (3.82): 45.Tg3 T8b7 46.Tg1 Tc7 47.Lc8 f5 48.Le6 Sxe6 49.dxe6 f4 50.Sf5 Sc6 51.La3 Tbb7 52.Sb3 Lf6 53.e7+ Txe7 54.Sxe7 Dxe7 55.Dg8+ Kxg8 56.gxf6+ Kf7 57.fxe7 Kxe7 58.Th1
4. +- (3.81): 45.Kg4 T8b7 46.Kf3 Tc7 47.Lc8 f5 48.Le6 fxe4+ 49.Sxe4 Lf7 50.Sf5 Lxe6 51.dxe6 Sxe6 52.Tf1 Sxc4 53.Kg2 Ke8 54.Dg6+ Kd7 55.Df7+ Kc6 56.Dxe6 Dd7 57.Sxg7 Se3+
5. +- (3.78): 45.Tg4 T8b7 46.Tg1 Tc7 47.Lc8 f5 48.Le6 fxe4+ 49.Sxe4 Lf7 50.Sf5 Lxe6 51.dxe6 Sxe6 52.Tf1 Sxc4 53.Kg2 Ke8 54.Dg8+ Kd7 55.Df7+ Kc6 56.Dxe6 Dd7 57.Sxg7 Dxg7 58.Tf6 Dh7 59.Dg4 Dd7 60.Dxd7+ Txd7 61.g6 Tg7 62.Lh6 Se3+ 63.Kf3
6. +- (3.52): 45.Dh2 Ta4 46.Dh7 De7 47.Lc8 f5 48.Sxf5 Lg6 49.Sxe7 Lxh7 50.Ld7 Kxe7 51.Lxa4 Lg6 52.La3 Th8 53.Th1 Tf8 54.Kg4 Sd3 55.Kg3 Sf2 56.Lc2 Sxh1+ 57.Txh1 Tb8 58.Sf3 Sxc4 59.Lc1 Kf7 60.Sh4 Lf8 61.Tf1+ Kg7 62.Tf6 Lh5 63.Th6 Ld1 64.Lxd1 Tb1 65.Sf5+ Kg8 66.Tg6+ Kh7 67.Te6 Kg8 68.Sxd6
7. +- (3.50): 45.La3 Ta4 46.Lc1 De7 47.Lc8 f5 48.Sxf5 Lg6 49.Sxe7 Lxh7 50.Ld7 Kxe7 51.Lxa4 Lg6 52.La3 Th8 53.Th1 Tf8 54.Kg4 Sd3 55.Kg3 Sf2 56.Tag1
8. +- (3.12): 45.Sdf1 Sxc4 46.Lc8 Dxc8 47.Sf5 Dxf5 48.exf5 Sxd5 49.Kf2 e4 50.f6 Sxf6 51.gxf6 Lxf6 52.Tg8+ Ke7 53.Lg5 Lxg5 54.Txg5 Ld7 55.Tg8 Tb2+ 56.Kg3 Le6 57.Txb8 Txb8 58.Te1 d5 59.Se3 Se5 60.Dg7 Sf3
9. +- (2.93): 45.Lh3 f5 46.Lxf5 Lf7 47.Tg4 Lg8 48.Dh1 Ke7 49.g6 De8 50.La3 Ta4 51.Dc1 Df8 52.Dc3 Tb7 53.Lb2 Lf6 54.Dc2 Tbb4 55.Lc3 Dh6 56.Sg2
10. +- (2.75): 45.Dh4 Sxc4 46.Sdxc4 Lb5 47.Sd2 Td4 48.Tb1 Le2+ 49.Kg3 Td3 50.Tb3 Tbxb3 51.Sxb3 c4 52.Sa1 Da5 53.Sac2 Lh5 54.Lg4 Lg6 55.Lf3 Da4 56.Se1 Tc3 57.S1g2 Sxg2
Peter.
-
Werewolf
- Posts: 2054
- Joined: Thu Sep 18, 2008 10:24 pm
Re: A good test for humans (and maybe engines under 2500?)
I think I can answer this.JVMerlino wrote: ↑Tue Sep 02, 2025 3:35 am In the latest CCRL Division 9, Myrddin reached this position against Roc and played the key move. I'm a total patzer, so I have no idea why it even works. If somebody could enlighten me (after you find it), I'd appreciate it!
[d]1r1qbk2/5pbQ/p2p4/n1pPpBP1/1rP1Pn2/4NK2/P2N4/R1B3R1 w - - 21 45
jm
White wants to put a knight on f5 instead of the bishop so he threatens, among other things, Qg7 mate. That's the basic plan.
But why can't white just move the bishop elsewhere like h3 or g4 or d7?
Because black has the defence ...f5 followed by ...Rb7 covering the Bg7 and stopping white's intended Qg7 mate.
So that would eliminate any bishop move behind the Nf5 like Bh3, for example, because white needs to be able to meet ...f5 with Nf5 and ...Rb7 with Be6! threatening mate on g8.
Bishop moves in front of the f5 square also fail. Bd7 fails for white because black can just take it with his bishop and when white plays Nf5 that also gets taken. So, by deduction, Bc8 is the only bishop move left.