Engine test: 41 mate in 4 puzzles from Classic Chess Puzzles

[Chessnut1071]

Hello Bill:

Code: Select all

FEN[130] = "3r1n2/2bp2p1/1p1kp1Pp/4N2p/Pp2B2Q/7P/1P3P1B/K7 w - - 0 1 "; // Philip Klett 4-move mate [Ba8, Bf3] - (25)

Chest 5.2 gives five solutions instead of two:

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FEN: 3r1n2/2bp2p1/1p1kp1Pp/4N2p/Pp2B2Q/7P/1P3P1B/K7 w - - 0 1

ChestUCI:
FEN: 3r1n2/2bp2p1/1p1kp1Pp/4N2p/Pp2B2Q/7P/1P3P1B/K7 w - -   (10+11)
Stellungs-Analyse:  C0/R0/K2/P6/X10   W:8/35
Suche nach Matt in 10 ...  (Hash=64MB)
   4	00:00	           0	0	+M4	Be4d3
   4	00:00	           0	0	+M4	Be4f3
   4	00:00	           0	0	+M4	Be4g2
   4	00:00	           0	0	+M4	Be4h1
   4	00:00	           0	0	+M4	Be4a8
Suche abgeschlossen ...  (Zeit=0.05s)
Matt in 4 gefunden !  (5 Lösungen in 00:00)
  4/4	00:00	      35.200	718.367	+M4	Be4a8 Bc7b8 f2f3 b4b3 Ne5f7+ Kd6c5 Bh2g1+
  4/4	00:00	      35.200	718.367	+M4	Be4h1 Bc7b8 b2b3 b6b5 Qh4xb4+ Kd6c7 Qb4c5+
  4/4	00:00	      35.200	718.367	+M4	Be4g2 Bc7b8 b2b3 b6b5 Qh4xb4+ Kd6c7 Qb4c5+
  4/4	00:00	      35.200	718.367	+M4	Be4f3 Bc7b8 b2b3 b6b5 Qh4xb4+ Kd6c7 Qb4c5+
  4/4	00:00	      35.200	718.367	+M4	Be4d3 Bc7b8 Ne5f7+ Kd6c6 Nf7xd8+ Kc6c5 Qh4c4+

I have not tried other problems, but there could be more solutions.

Regards from Spain.

Ajedrecista.

Whoops, that's Philip Klett's 4-move mate FEN[130]. Yes there are a range of solutions on that one too.

[Ajedrecista]

Hello Bill:

[...]

There may be one other 4-move mate with multiple solutions. Back then they didn't have computer assistance.

So the provided solutions are the original intended solutions instead of all the solutions. It is good to know, for example if people start getting other moves that are correct and not listed. Thank you.

Regards from Spain.

Ajedrecista.

[eduherminio]

Given that I've already spent a few minutes preparing it, in case it's useful for anyone else:
"<sanitized fen>" | "<uci_move>", "uci_move"

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"n7/3p1p2/NpkNp1p1/1p2P3/3Q4/6B1/b7/4K3 w - - 0 1" | "d4g1"
"K6Q/1p6/pPq4P/P2p2P1/4pP1N/7k/n5R1/1n2BB2 w - - 0 1" | "f1a6"
"8/8/8/3p4/1N1P2Kp/Bkp5/5Q2/4N3 w - - 0 1" | "f2f8"
"4K3/8/pp2B3/P7/4kpR1/2P1p3/4Q3/2r5 w - - 0 1" | "g4g2"
"8/Q5p1/2Bpq3/KPn2pR1/3kpP1p/1P1p3b/3B1b2/7n w - - 0 1" | "g5g6"
"2Q3Kn/p7/8/3NkPp1/p7/P1Np1pPr/1P1p4/1b2b2r w - - 0 1" | "b2b4"
"4b1N1/2pr2pR/2rp1p2/1Q1B1kp1/2pP4/4P1K1/1n3PN1/R7 w - - 0 1" | "a1g1"
"r1b5/1p1n3p/4p2K/p5Bp/3k4/Q4B2/2P5/5n2 w - - 0 1" | "g5e7"
"4N3/1p6/3B2nN/pPpk4/4R1Pp/P1p2P2/K1P1b3/3n4 w - - 0 1" | "d6h2"
"3r1n2/2bp2p1/1p1kp1Pp/4N2p/Pp2B2Q/7P/1P3P1B/K7 w - - 0 1" | "e4g2", "e4d3", "e4b1", "e4f1", "e4a8"
"3K4/8/6R1/p3k1pp/2bp1R1p/n1b1P3/2p2N2/2B4B w - - 0 1" | "g6g5", "c1d2"
"5n2/r2p1p2/p1PBkn2/p3Ppp1/6b1/1N1pP3/1N1P3K/2R5 w - - 0 1" | "b2a4"
"8/1Qp5/2K5/1R5p/7P/5k2/8/8 w - - 0 1" | "b5a5"
"8/8/8/p7/R4B2/8/5k2/1B5K w - - 0 1" | "b1f5"
"2N5/8/N1B5/4k2p/8/7K/8/2Q5 w - - 0 1" | "h3h4"
"8/1R6/8/3k3N/N5R1/8/8/4K3 w - - 0 1" | "g4g7"
"8/1R4p1/3kN3/5PR1/8/6K1/8/8 w - - 0 1" | "f5f6"
"8/8/2K3p1/4N2B/7k/5p2/Q7/8 w - - 0 1" | "a2b1"
"1n6/2Bp4/p2N4/N1k5/2p1P3/R1P5/1P6/1K1b4 w - - 0 1" | "a3a4"
"2r5/2p3n1/5R2/4k1PP/3R2p1/2n1P3/1Q2P3/4b2K w - - 0 1" | "b2b7"
"8/8/1p6/1P1P1B2/k7/1NK5/2N5/8 w - - 0 1" | "c2e3"
"4nKn1/1Q6/2p2P2/1p6/6r1/2P1B3/1N1Np1b1/4k3 w - - 0 1" | "b7f7"
"8/np1N1N2/4p3/1p1b4/1b2kp2/p1R5/p3P3/n1Q2K2 w - - 0 1" | "c3g3"
"bK1N2N1/5Qnr/2p4p/2pnk3/8/1p1BPP2/6rp/7q w - - 0 1" | "d3c4"
"1QB3n1/BK4P1/4Pp1r/p2kb2p/7P/5Rp1/1PP2Pp1/8 w - - 0 1" | "e6e7"
"n7/3rp1NK/b4pP1/1r6/4kb2/p4R2/qNP2R1P/1n5B w - - 0 1" | "f3f4"
"8/1pp5/2b5/4N3/2Q2B2/k1p4r/p5rp/K1R5 w - - 0 1" | "f4h6"
"2k5/K2pR3/RB1p1r2/1p4N1/1p4N1/1P6/6n1/3Br2q w - - 0 1" | "a6a2"
"4b3/3q4/8/4P3/4BP1p/1R1Pk2p/4N3/4K2R w - - 0 1" | "e4a8"
"1KB1n3/Q4p1N/1Npk3q/r1p5/2p2p1b/R1p4b/2P2P2/4R3 w - - 0 1" | "a3a1"
"8/8/8/4p3/4p3/2k5/2P1K3/1R1R4 w - - 0 1" | "b1b5"
"4k3/5RR1/8/1n6/8/7p/7K/8 w - - 0 1" | "g7h7"
"8/8/8/3R4/8/5K2/4n2p/7k w - - 0 1" | "d5d2"
"8/8/3K4/6p1/3k3P/1R1P1R2/8/8 w - - 0 1" | "f3h3"
"R7/8/1p4K1/1Pp4P/1P1p2pk/2pR4/P5P1/8 w - - 0 1" | "a8a3"
"7R/8/8/4N3/1p5p/4K2p/8/4k3 w - - 0 1" | "h8c3"
"6R1/8/8/3N4/p5p1/3K2p1/8/3k4 w - - 0 1" | "g8e8"
"3k4/5R2/8/8/2K5/B3N3/8/8 w - - 0 1" | "e3f5"
"3k4/7R/8/8/K2B1N2/8/8/8 w - - 0 1" | "f4d3"
"3k4/6R1/8/8/1N1B4/3K4/8/8 w - - 0 1" | "d4e3"
"3k4/7R/8/8/1N1B4/2K5/8/8 w - - 0 1" | "b4d3"

I may have, of course, missed/confused some extra solutions; but I tried to verify them with lichess analysis mode.

[Brunetti]

"3r1n2/2bp2p1/1p1kp1Pp/4N2p/Pp2B2Q/7P/1P3P1B/K7 w - - 0 1" | "e4g2", "e4d3", "e4b1", "e4f1", "e4a8"

Here e4f1 is not valid, it should be e4f3.

"7R/8/8/4N3/1p5p/4K2p/8/4k3 w - - 0 1" | "h8c3"
I may have, of course, missed/confused some extra solutions; but I tried to verify them with lichess analysis mode.

The correct move is h8c8 and not h8c3.

Alex

[eduherminio]

"3r1n2/2bp2p1/1p1kp1Pp/4N2p/Pp2B2Q/7P/1P3P1B/K7 w - - 0 1" | "e4g2", "e4d3", "e4b1", "e4f1", "e4a8"

Here e4f1 is not valid, it should be e4f3.

Indeed, the right solutions seem to be:

Code: Select all

"3r1n2/2bp2p1/1p1kp1Pp/4N2p/Pp2B2Q/7P/1P3P1B/K7 w - - 0 1" | "e4g2", "e4d3", "e4h1", "e4f3", "e4a8"

Thanks!