I composed a two-mover based on other interesting-to-me 5+0 game that I lost on time, where I missed some checkmate in N moves in an interesting king hunt. I did not save the game, by the way.
I rearranged the white knight (on c3 in the original game) and added other black pieces to increase the difficulty for engines. The surprise came when SF 17 needed depth 25 (!) to find the correct solution (there are two solutions indeed). First of all, here is the position:
[d]2rr4/3R3n/b4p1p/8/2p1R1P1/pp3kNP/5P1n/6K1 w - - 0 1
I friendly challenge you to solve the problem on your own before running any engine.
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After all of you have solved it, this is the time to say that the conditions of SF 17 search were single core and Multi-PV disabled, to get deterministic results:
Code: Select all
FEN: 2rr4/3R3n/b4p1p/8/2p1R1P1/pp3kNP/5P1n/6K1 w - - 0 1
Stockfish-17-windows-x86-64-sse41-popcnt:
Found 145 WDL and 145 DTZ tablebase files (up to 5-man).
Available processors: 0-3
Using 1 thread
NNUE evaluation using nn-1111cefa1111.nnue (133MiB, (22528, 3072, 15, 32, 1))
NNUE evaluation using nn-37f18f62d772.nnue (6MiB, (22528, 128, 15, 32, 1))
1/4 00:00 44 22.000 -3,08 Rd7xd8 Rc8xd8
[...]
5/4 00:00 191 95.500 -3,08 Rd7xd8 Rc8xd8
6/8 00:00 274 137.000 -2,89 Re4e3+ Kf3f4 Re3e4+ Kf4g5
7/8 00:00 338 169.000 -2,93 Re4e3+ Kf3f4 Re3e4+ Kf4g5
8/11 00:00 621 207.000 -1,75 Re4e3+ Kf3f4 Ng3e2+ Kf4g5 Rd7g7+ Kg5h4 Kg1xh2
9/10 00:00 696 232.000 -1,88 Re4e3+ Kf3f4 Ng3e2+ Kf4g5 Rd7g7+ Kg5h4 Kg1xh2 c4c3 Ne2xc3
10/12 00:00 2.372 338.857 -0,94 Re4e3+ Kf3f4 Re3e4+ Kf4g5 Rd7g7+ Kg5h4
11/10 00:00 2.872 359.000 0,00 Re4e3+ Kf3f4 Re3e4+ Kf4f3 Re4e3+
12/5 00:00 2.961 370.125 0,00 Re4e3+ Kf3f4 Re3e4+ Kf4f3
[...]
23/5 00:00 6.392 456.571 0,00 Re4e3+ Kf3f4 Re3e4+ Kf4f3
24/14 00:00 10.383 432.625 +2,68 Re4e3+ Kf3f4 Re3e4+ Kf4f3 Re4e5 Rc8c5 Re5xc5 c4c3 Rc5xc3+ Kf3f4 Rd7xd8
25/20 00:00 15.762 404.153 +M3 Re4e5 Rc8c5 Re5xc5 c4c3 Rc5f5+
26/6 00:00 16.432 410.800 +M3 Re4e5 Rc8c5 Re5xc5 c4c3 Rc5f5+
27/6 00:00 17.075 426.875 +M3 Re4e5 Rc8c5 Re5xc5 c4c3 Rc5f5+
[...]
244/6 00:01 277.733 263.004 +M3 Re4e5 Rc8c5 Re5xc5 c4c3 Rc5f5+
245/6 00:01 278.907 264.116 +M3 Re4e5 Rc8c5 Re5xc5 c4c3 Rc5f5+[Site "Madrid (Spain)"]
[Round ""]
[Date "2025.10.15"]
[SetUp "1"]
[FEN "2rr4/3R3n/b4p1p/8/2p1R1P1/pp3kNP/5P1n/6K1 w - - 0 1"]
[PlyCount "5"]
[Result "1-0"]
1. Re5 fxe5 (1. ... Rc5 (1. ... Rxd7 2. Rf5#) 2. Rxc5 Rxd7 {(any)} 3. Rf5#) 2. Rf7+ Nf6 3. Rxf6# 1-0[/pgn]
OTOH, here is AnMon 5.60 from year 2006:
Code: Select all
FEN: 2rr4/3R3n/b4p1p/8/2p1R1P1/pp3kNP/5P1n/6K1 w - - 0 1
AnMon 5.60:
1+ 00:00 3 0 -7,54 Rd7xh7
1 00:00 4 0 -7,54 Rd7xh7
1+ 00:00 18 0 -7,53 Re4e3+ Kf3f4 Ng3h5+ Kf4g5 Rd7g7+ Kg5h4 Rg7xh7
1 00:00 84 0 -7,43 Re4e3+ Kf3f4 Rd7xh7
2 00:00 391 0 -7,35 Re4e3+ Kf3f4 Ng3h5+ Kf4g5 f2f4+ Kg5h4 Rd7xh7
2+ 00:00 1.520 0 -7,24 Re4e5 Ba6b7 Rd7xb7 Rd8d1+ Kg1xh2 f6xe5 Rb7xh7 Kf3xf2 Rh7xh6
2 00:00 1.810 0 -4,90 Re4e5 Rc8c5 Re5xc5
3+ 00:00 2.565 0 +M3 Re4e5 Rc8c5 Re5xc5 Ba6c8 Rc5f5+
3 00:00 2.603 0 +M3 Re4e5 Rc8c5 Re5xc5 Ba6c8 Rc5f5+------------
I had lost two games against the same player before and I felt he/she was stronger than me. I sacrificed a piece for a pawn in the third game, attempting a threefold repetition that was enough for me. There was not a threefold repetition and a funny king hunt began. Once again, a change of plans led to interesting motifs, like here. Digging deep in my memory, I had reconstructed the game completely after hours of playing it, quite a feat for me:
[pgn][Event ""]
[Site ""]
[Round ""]
[Date "2025.10.15"]
[PlyCount "80"]
[Result "0-1"]
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 c6 5. cxd5 exd5 6. Nf3 Bd6 7. e3 O-O 8. Bd3 Nbd7 9. Rc1 b6 10. Na4 Bb7 11. Qe2 a5 12. O-O Re8 13. a3 Nf8 14. Bxf6 gxf6 15. Nh4 Ng6 16. Qg4 Bc8 17. Qh5 Bd7 18. Bxg6 fxg6 19. Nxg6 hxg6 20. Qxg6+ Kf8 21. Qh6+ Kf7 22. Qh7+ Ke6 23. e4 Rh8 24. exd5+ Kxd5 25. Nc3+ Kc4 26. Qf7+ Kxd4 27. Rcd1+ Ke5 28. Rfe1+ Kf4 29. Rxd6 Rf8 30. Qxd7 Qxd7 31. Rxd7 Rac8 32. h3 Kf5 33. g4+ Kf4 34. Rg7 Kf3 35. Rd7 Rcd8 (35. ... Rfd8 36. Re5) 36. Rxd8 Rxd8 37. Re3+ Kf4 38. Kg2 Rd2 39. Ne2+ Kg5 40. Kg3 Rxb2 {(white lost on time)} 0-1[/pgn]
I played Rd7 (from g7), threatening Rd3# and black instantly played ..., Rcd8 instead of ..., Rfd8 (a losing move that gave me the idea to compose the problem). It is needless to say that I would have never found the key move after ..., Rfd8.
Regards from Spain.
Ajedrecista.
