12 monkeys by Walter Eigenmann (7 are tough nuts to crack)

[User923005]

Walter Eigenmann's 12 monkeys test set analysed (5 right out of 12) {mixed analysis with several high end programs, chosen best records so far):
1k5r/pb3p1p/1q2rp1b/2p5/1pQ1P3/1P3N2/P3BPPP/3R1RK1 w - - acd 35; acs 553; bm Rd5; c0 Karpov-Gelfand, 1993, Linares; cce 0; ce 44; id Monkey 01: Der Schöne (The Beauty); pm Bd3; pv Bd3 Rd8 Qc2 Red6 h4 R8d7 Be2 Rxd1 Bxd1 Qd8 Be2 Qe7;
r4rk1/ppnqp2p/3p2p1/2pP4/P1P2B1P/6P1/1P3PK1/R2Q1R2 b - - acd 33; acs 5626; bm Rxf4; c0 Tyomkin-McDonald, 2001, Oakham GM; ce -8; id Monkey 02: Der Hässliche (The Ugly); pm e6; pv e6 dxe6 Qc6+ f3 Nxe6 Bh6 Rfe8 Ra3 Nd4 Be3 Nf5 Bf2 h5 a5 Re7 Re1 Rae8 Rxe7 Rxe7 Qd2 Kh7 b4 cxb4 Qxb4 Re2 Rb3 b6 Kg1 Rc2 axb6 axb6 Qxb6 Qxb6 Rxb6 Rxc4 Rb2 Kg7 Kg2 d5 Kf1 d4 g4 hxg4 fxg4;
3r1rk1/1Qp1q2p/4p3/p7/Pn1b1p1P/2N3P1/1P3PB1/2RR2K1 w - - acd 32; acs 579; bm Rxd4; c0 Akesson-Stefansson, 1997, Nordic-ch; ce 0; id Monkey 03: Der Gute (The Good); pm Rxd4; pv Rxd4 Rxd4 Ne2 Rd7 Nxf4 c6 Qb6 e5 Nh3 Qd8 Qe3 Rdf7 Rc4 Qd1+ Kh2 Nd3 Rxc6 Nxf2 Nxf2 Rxf2 Qg5+ Kh8 Qxe5+ Kg8 Qg5+ Kh8 Qe5+ Kg8 Qg5+ Kh8 Qe5+;
r2br1k1/1q3ppp/p2B4/Pp1pN3/3Pb1P1/1QP2P2/7P/R3R1K1 b - - acd 34; acs 542; bm Rxe5; c0 PengXiaomin-Motylev, 2001, CHN-RUS; ce 149; id Monkey 04: Der Böse (The Bad); pm Rxe5; pv Rxe5 Bxe5 Bxf3 Re3;
8/3r4/p5kp/Pb1R4/1P1B2P1/6P1/3K4/8 w - - acd 48; acs 508; bm Rxb5; c0 Romanishin-Smagin, 2001, Julian Borowski; ce 286; id Monkey 05: Der Exakte (The Exact); pm Rxb5; pv Rxb5 axb5 Kd3 Rd6 Ke4 Kf7 Ke5 Rg6 Kd5 Ke8 Kc5 Kd8 Kxb5 Rxg4 a6 Kc8 Bf2 h5 Ka5 h4 gxh4 Rf4 Be1 Re4 Bg3 Rg4 Bd6 Rxh4 Kb5 Rg4 Kc5 Rg1 b5 Rc1+ Kd5 Rb1 Kc6 Ra1 Kb6 Rb1;
5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - acd 38; acs 429; bm Rxb5; c0 Ionov-Sergienko, 1999, RUS-chT; ce 0; id Monkey 06: Der Spekulative (The Speculative); pm Bc8; pv Bc8 O-O-O Qf7 Rh1 Qf5 Qg3 Bd7 Rh4 Ne7 Rg4 Qf7 Ng5 Qf5 Nf3 Qf7 Ng5 Qf5 Nf3;
3rrnk1/p1n1qpp1/1p5p/2pRP3/2P4P/1P2Q1PB/PB5K/4R3 w - - acd 35; acs 558; bm Red1; c0 Movsesian-Sokolov, 1999, EU-chT; ce 48; id Monkey 07: Der Stürmische (The Stormy); pm Rdd1; pv Rdd1 Ng6 Rxd8 Qxd8 Qe2 Ne6 Rd1 Qc7 Qe4 Nd4 Bxd4;
2nqr1k1/5p2/1p4pp/pP1rNn2/P4P2/BQ1p4/6PP/2RR2K1 b - - acd 37; acs 542; bm Rdxe5; c0 Mortensen-Van der Weide, 1998, Reykjavik; ce 20; id Monkey 08: Der Berechnende (The Calculating); pm Rdxe5; pv Rdxe5 fxe5 Qd4+ Kh1 d2 Rc7 Ncd6 Bxd6 Nxd6 Rf1 Qxe5 Rcxf7 Qe6 Qxe6 Rxe6 Rd7 g5 Kg1 h5 g3 g4 Kf2 Rf6+ Ke2 Rxf1 Rxd6 d1Q+ Rxd1 Rxd1 Kxd1 Kf7 Kd2 Ke6 Ke2 Kd6 Kd2 Ke6 Ke2 Kd6 Kd2 Ke6;
r1b2rk1/pp3pb1/3q2pp/2nP4/6P1/2P2N2/P1Q1BPP1/2BR1RK1 w - - acd 33; acs 2682; bm Rd4; c0 Zakharevich-Guliev, 1997, Chigorin memorial; cce 0; ce 55; id Monkey 09: Der Originelle (The Original); pm Nd4; pv Nd4 Bd7;
2r1rbk1/p1qn2p1/3n1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1BR1BK1 w - - acd 33; acs 5622; bm Rxd6; c0 Minasian-Jonkman, 2000, Anibal op; ce 72; id Monkey 10: Der Freche (The Cheeky); pm Be3; pv Be3 c4 Nd2 Nb8 b3 c3 Nc4 Nf7 Rd5 Nc6 h4 Ne7 Rd3 Rcd8 Rad1 Rxd3 Rxd3 Nc6 Rd5 Rd8 Qd1 Nd4 Bxd4 Rxd5 exd5 exd4 Qf3 g5 h5 Qf4 Kg2 Qxf3+ Kxf3 Bc5 Ke4 Kf8 Be2 Ke7 Kf5 Nd6+ Kg6 Nxc4 Bxc4 Kf8 a6 Bd6 Bd3 Bc7;
r1r3k1/1bq2pp1/p4n1p/1p1npB2/PP6/2P2N2/1BQ2PPP/R3R1K1 b - - acd 33; acs 549; bm Nf4; c0 Svetushkin-Kruppa, 2000, Kiev; ce 44; id Monkey 11: Der Romantische (The Romantic); pm Re8; pv Re8 axb5 axb5 Rxa8 Bxa8 Bc1;
2q2rk1/2p2pb1/PpP1p1pp/2n5/5B1P/3Q2P1/4PPN1/2R3K1 w - - acd 35; acs 502; bm Rxc5; c0 Dolinskij-Tosic, 1999, Geller memorial; ce 16; id Monkey 12: Der Unbarmherzige (The Pitiless); pm Rxc5; pv Rxc5 bxc5 a7 Rd8 Qb5 c4 Be3 c3 Ne1 Kh7 Nd3 f5;

Houdini 3. 2 hour analysis for the 7 unsolved position (4CPU 3.4 GHz I7) all 7 are still missed:
r4rk1/ppnqp2p/3p2p1/2pP4/P1P2B1P/6P1/1P3PK1/R2Q1R2 b - - acd 33/77; acs 5626 ; acn 61807670343; ce -8 ; bm e6; pv e6 dxe6 Qc6+ f3 Nxe6 Bh6 Rfe8 Ra3 Nd4 Be3 Nf5 Bf2 h5 a5 Re7 Re1 Rae8 Rxe7 Rxe7 Qd2 Kh7 b4 cxb4 Qxb4 Re2 Rb3 b6 Kg1 Rc2 axb6 axb6 Qxb6 Qxb6 Rxb6 Rxc4 Rb2 Kg7 Kg2 d5 Kf1 d4 g4 hxg4 fxg4;
r1r3k1/1bq2pp1/p4n1p/1p1npB2/PP6/2P2N2/1BQ2PPP/R3R1K1 b - - acd 32/77; acs 4853 ; acn 54399891222; ce 30 ; bm Re8; pv Re8 axb5 axb5 Rxa8 Bxa8 Bc1 Nb6 Nd2 Rd8 h3 Nfd5 Nf3 Nc4 Bh7+ Kh8 Bd3 f6 Nh4 Ne7 Rd1 g5 Bxc4 Rxd1+ Qxd1 bxc4 Nf3 Kg7 Ne1 Nd5 Bd2 Qd6 Qe2 Qa6 Qg4 Bc6 Qe6 Qb7 Qg4 Qb5 Nf3 Qa6 Qe6 Qa1+ Kh2;
r1b2rk1/pp3pb1/3q2pp/2nP4/6P1/2P2N2/P1Q1BPP1/2BR1RK1 w - - acd 33/71-; acs 2682 ; acn 29137302910; ce 55 ; bm Nd4; pv Nd4 Bd7;
5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - acd 36/80; acs 5032 ; acn 56819152750; ce 0 ; bm Bc8; pv Bc8 Kd2 Qf7 Rh1 Qf5 Qxf5 Rxf5 Ng5 h6 Nh3 Rf8 g4 Kf7 g5 h5 g6+ Kxg6 Nf4+ Kf7 Rxh5 Ne7 Rh1 Bd7 Nh3 Nf5 Nf4 Rc8 Rb1 Rb8 Rh1 Re8 Rb1 b6 Rh1 Rc8 Rh7 Kg8 Rh1 Kf7 Rh7;
3rrnk1/p1n1qpp1/1p5p/2pRP3/2P4P/1P2Q1PB/PB5K/4R3 w - - acd 33/77; acs 3545 ; acn 39110222351; ce 30 ; bm Rxd8; pv Rxd8 Rxd8 Bg2 Nfe6 Bc3 Qd7 Rf1 Qd3 Qf2 Qg6 Qe1 Nd4 Be4 Qe6 Qe3 Re8 Bxd4 cxd4 Qf3 Re7 Re1 Qc8 Kg2 Qa6 Rf1 Qc8 Rd1 Rxe5 Rxd4 Qe8 Qd3 Ne6 Rd5 Rxd5 Bxd5 Qe7 Qe4 Qa3 Qe2 Qd6 Qe3 Nc7 Bf3 Ne6 Qe2;
2r1rbk1/p1qn2p1/3n1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1BR1BK1 w - - acd 33/84; acs 5622 ; acn 59272448536; ce 72 ; bm Be3; pv Be3 c4 Nd2 Nb8 b3 c3 Nc4 Nf7 Rd5 Nc6 h4 Ne7 Rd3 Rcd8 Rad1 Rxd3 Rxd3 Nc6 Rd5 Rd8 Qd1 Nd4 Bxd4 Rxd5 exd5 exd4 Qf3 g5 h5 Qf4 Kg2 Qxf3+ Kxf3 Bc5 Ke4 Kf8 Be2 Ke7 Kf5 Nd6+ Kg6 Nxc4 Bxc4 Kf8 a6 Bd6 Bd3 Bc7;
1k5r/pb3p1p/1q2rp1b/2p5/1pQ1P3/1P3N2/P3BPPP/3R1RK1 w - - acd 33/71; acs 2519 ; acn 27487189957; ce 28 ; bm Bd3; pv Bd3 Qc7 Nh4 Bf4 g3 Be5 Qc2 Bc3 Nf5 Re5 f3 Bc8 Kh1 Bxf5 exf5 Bd4 Qc4 h5 Rfe1 h4 Kg2 Qa5 Bb1 Qc7 Be4 Rd8 Re2 Re7;

Now, considering that the test is by Walter Eigenmann, I have little doubt that the stated answers really are best moves. I just have not mechanically found them yet. Anyone else find a solution for them?

[Jeremy Bernstein]

r4rk1/ppnqp2p/3p2p1/2pP4/P1P2B1P/6P1/1P3PK1/R2Q1R2 b - - acd 33/77; acs 5626 ; acn 61807670343; ce -8 ; bm e6; pv e6 dxe6 Qc6+ f3 Nxe6 Bh6 Rfe8 Ra3 Nd4 Be3 Nf5 Bf2 h5 a5 Re7 Re1 Rae8 Rxe7 Rxe7 Qd2 Kh7 b4 cxb4 Qxb4 Re2 Rb3 b6 Kg1 Rc2 axb6 axb6 Qxb6 Qxb6 Rxb6 Rxc4 Rb2 Kg7 Kg2 d5 Kf1 d4 g4 hxg4 fxg4;
r1r3k1/1bq2pp1/p4n1p/1p1npB2/PP6/2P2N2/1BQ2PPP/R3R1K1 b - - acd 32/77; acs 4853 ; acn 54399891222; ce 30 ; bm Re8; pv Re8 axb5 axb5 Rxa8 Bxa8 Bc1 Nb6 Nd2 Rd8 h3 Nfd5 Nf3 Nc4 Bh7+ Kh8 Bd3 f6 Nh4 Ne7 Rd1 g5 Bxc4 Rxd1+ Qxd1 bxc4 Nf3 Kg7 Ne1 Nd5 Bd2 Qd6 Qe2 Qa6 Qg4 Bc6 Qe6 Qb7 Qg4 Qb5 Nf3 Qa6 Qe6 Qa1+ Kh2;
r1b2rk1/pp3pb1/3q2pp/2nP4/6P1/2P2N2/P1Q1BPP1/2BR1RK1 w - - acd 33/71-; acs 2682 ; acn 29137302910; ce 55 ; bm Nd4; pv Nd4 Bd7;
5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - acd 36/80; acs 5032 ; acn 56819152750; ce 0 ; bm Bc8; pv Bc8 Kd2 Qf7 Rh1 Qf5 Qxf5 Rxf5 Ng5 h6 Nh3 Rf8 g4 Kf7 g5 h5 g6+ Kxg6 Nf4+ Kf7 Rxh5 Ne7 Rh1 Bd7 Nh3 Nf5 Nf4 Rc8 Rb1 Rb8 Rh1 Re8 Rb1 b6 Rh1 Rc8 Rh7 Kg8 Rh1 Kf7 Rh7;
3rrnk1/p1n1qpp1/1p5p/2pRP3/2P4P/1P2Q1PB/PB5K/4R3 w - - acd 33/77; acs 3545 ; acn 39110222351; ce 30 ; bm Rxd8; pv Rxd8 Rxd8 Bg2 Nfe6 Bc3 Qd7 Rf1 Qd3 Qf2 Qg6 Qe1 Nd4 Be4 Qe6 Qe3 Re8 Bxd4 cxd4 Qf3 Re7 Re1 Qc8 Kg2 Qa6 Rf1 Qc8 Rd1 Rxe5 Rxd4 Qe8 Qd3 Ne6 Rd5 Rxd5 Bxd5 Qe7 Qe4 Qa3 Qe2 Qd6 Qe3 Nc7 Bf3 Ne6 Qe2;
2r1rbk1/p1qn2p1/3n1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1BR1BK1 w - - acd 33/84; acs 5622 ; acn 59272448536; ce 72 ; bm Be3; pv Be3 c4 Nd2 Nb8 b3 c3 Nc4 Nf7 Rd5 Nc6 h4 Ne7 Rd3 Rcd8 Rad1 Rxd3 Rxd3 Nc6 Rd5 Rd8 Qd1 Nd4 Bxd4 Rxd5 exd5 exd4 Qf3 g5 h5 Qf4 Kg2 Qxf3+ Kxf3 Bc5 Ke4 Kf8 Be2 Ke7 Kf5 Nd6+ Kg6 Nxc4 Bxc4 Kf8 a6 Bd6 Bd3 Bc7;
1k5r/pb3p1p/1q2rp1b/2p5/1pQ1P3/1P3N2/P3BPPP/3R1RK1 w - - acd 33/71; acs 2519 ; acn 27487189957; ce 28 ; bm Bd3; pv Bd3 Qc7 Nh4 Bf4 g3 Be5 Qc2 Bc3 Nf5 Re5 f3 Bc8 Kh1 Bxf5 exf5 Bd4 Qc4 h5 Rfe1 h4 Kg2 Qa5 Bb1 Qc7 Be4 Rd8 Re2 Re7;

In a quick test:

1. Komodo 5 finds ...e6 instantly
2. Komodo 5 finds ...Re8 instantly
3. Komodo 5 finds Nd4 after a slight hesitation
4. Komodo 5 finds ...Bc8 at depth 20, after about 30 seconds on a fast machine
5. Komodo 5 finds Rxd8 nearly instantly
6. Komodo 5 settles on Be3 after about 10 seconds, but then switches to a6 at around d20 and sticks with it
7. Komodo 5 finds Bd3 instantly

I have trouble believing that Houdini doesn't find these moves, though. Or is that not the information you wanted?

Jeremy

[User923005]

No, those are the moves Houdini found, and Stockfish too. Not to mention Critter and some others.
However, those are not the right answers. Look at the set declaration above those records and see that the bm does not match the pm. The original bm is what is wanted.
The original post was rather noisy. Here is a simplified set, reflecting the original problems:
1k5r/pb3p1p/1q2rp1b/2p5/1pQ1P3/1P3N2/P3BPPP/3R1RK1 w - - bm Rd5; c0 Karpov-Gelfand, 1993, Linares; id Monkey 01: Der Schöne (The Beauty);
r4rk1/ppnqp2p/3p2p1/2pP4/P1P2B1P/6P1/1P3PK1/R2Q1R2 b - - bm Rxf4; c0 Tyomkin-McDonald, 2001, Oakham GM; id Monkey 02: Der Hässliche (The Ugly);
3r1rk1/1Qp1q2p/4p3/p7/Pn1b1p1P/2N3P1/1P3PB1/2RR2K1 w - - bm Rxd4; c0 Akesson-Stefansson, 1997, Nordic-ch; id Monkey 03: Der Gute (The Good);
r2br1k1/1q3ppp/p2B4/Pp1pN3/3Pb1P1/1QP2P2/7P/R3R1K1 b - - bm Rxe5; c0 PengXiaomin-Motylev, 2001, CHN-RUS; id Monkey 04: Der Böse (The Bad);
8/3r4/p5kp/Pb1R4/1P1B2P1/6P1/3K4/8 w - - bm Rxb5; c0 Romanishin-Smagin, 2001, Julian Borowski; id Monkey 05: Der Exakte (The Exact);
5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - bm Rxb5; c0 Ionov-Sergienko, 1999, RUS-chT; ce 0; id Monkey 06: Der Spekulative (The Speculative);
3rrnk1/p1n1qpp1/1p5p/2pRP3/2P4P/1P2Q1PB/PB5K/4R3 w - - bm Red1; c0 Movsesian-Sokolov, 1999, EU-chT; ce 48; id Monkey 07: Der Stürmische (The Stormy);
2nqr1k1/5p2/1p4pp/pP1rNn2/P4P2/BQ1p4/6PP/2RR2K1 b - - bm Rdxe5; c0 Mortensen-Van der Weide, 1998, Reykjavik; id Monkey 08: Der Berechnende (The Calculating);
r1b2rk1/pp3pb1/3q2pp/2nP4/6P1/2P2N2/P1Q1BPP1/2BR1RK1 w - - bm Rd4; c0 Zakharevich-Guliev, 1997, Chigorin memorial; id Monkey 09: Der Originelle (The Original);
2r1rbk1/p1qn2p1/3n1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1BR1BK1 w - - bm Rxd6; c0 Minasian-Jonkman, 2000, Anibal op; id Monkey 10: Der Freche (The Cheeky);
r1r3k1/1bq2pp1/p4n1p/1p1npB2/PP6/2P2N2/1BQ2PPP/R3R1K1 b - - bm Nf4; c0 Svetushkin-Kruppa, 2000, Kiev; id Monkey 11: Der Romantische (The Romantic);
2q2rk1/2p2pb1/PpP1p1pp/2n5/5B1P/3Q2P1/4PPN1/2R3K1 w - - bm Rxc5; c0 Dolinskij-Tosic, 1999, Geller memorial; id Monkey 12: Der Unbarmherzige (The Pitiless);
It is these bm values that are to be matched.

[Jeremy Bernstein]

Ah ok, retesting at 30min with Komodo 5

[User923005]

My next move will probably be to force the suggested move and analyze that position at long time control.
Often, that technique sees the solution when regular analysis won't.
I might also try idea searches, but I am not sure how to guide this kind of a search.

[User923005]

Here is the follow-on set:
r5k1/ppnqp2p/3p2p1/2pP4/P1P2r1P/6P1/1P3PK1/R2Q1R2 w - - c0 "After move Rxf4 has been made.";
r1r3k1/1bq2pp1/p4n1p/1p2pB2/PP3n2/2P2N2/1BQ2PPP/R3R1K1 w - - c0 "After move Nf4 has been made.";
r1b2rk1/pp3pb1/3q2pp/2nP4/3R2P1/2P2N2/P1Q1BPP1/2B2RK1 b - - c0 "After move Rd4 has been made.";
6k1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1Br1Q/2P2PP1/R3K3 w Q - c0 "After move Rxf3 has been made.";
3rrnk1/p1n1qpp1/1p5p/2p1P3/2P4P/1P2Q1PB/PB5K/3RR3 b - - c0 "After move Red1 has been made.";
2r1rbk1/p1qn2p1/3R1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1B2BK1 b - - c0 "After move Rxd6 has been made.";
1k5r/pb3p1p/1q2rp1b/2pR4/1pQ1P3/1P3N2/P3BPPP/5RK1 b - - c0 "After move Rd5 has been made.";

[User923005]

This is my "prime the pump" set, which should work well unless the hash table is cleared between moves.
r5k1/ppnqp2p/3p2p1/2pP4/P1P2r1P/6P1/1P3PK1/R2Q1R2 w - - c0 "After move Rxf4 has been made.";
r5k1/ppnqp2p/3p2p1/2pP4/P1P2r1P/6P1/1P3PK1/R2Q1R2 w - - bm Rxf4;
r1r3k1/1bq2pp1/p4n1p/1p2pB2/PP3n2/2P2N2/1BQ2PPP/R3R1K1 w - - c0 "After move Nf4 has been made.";
r1r3k1/1bq2pp1/p4n1p/1p2pB2/PP3n2/2P2N2/1BQ2PPP/R3R1K1 w - - bm Nf4;
r1b2rk1/pp3pb1/3q2pp/2nP4/3R2P1/2P2N2/P1Q1BPP1/2B2RK1 b - - c0 "After move Rd4 has been made.";
r1b2rk1/pp3pb1/3q2pp/2nP4/3R2P1/2P2N2/P1Q1BPP1/2B2RK1 b - - bm Rd4;
6k1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1Br1Q/2P2PP1/R3K3 w Q - c0 "After move Rxf3 has been made.";
6k1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1Br1Q/2P2PP1/R3K3 w Q - bm Rxf3;
3rrnk1/p1n1qpp1/1p5p/2p1P3/2P4P/1P2Q1PB/PB5K/3RR3 b - - c0 "After move Red1 has been made.";
3rrnk1/p1n1qpp1/1p5p/2p1P3/2P4P/1P2Q1PB/PB5K/3RR3 b - - bm Red1;
2r1rbk1/p1qn2p1/3R1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1B2BK1 b - - c0 "After move Rxd6 has been made.";
2r1rbk1/p1qn2p1/3R1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1B2BK1 b - - bm Rxd6;
1k5r/pb3p1p/1q2rp1b/2pR4/1pQ1P3/1P3N2/P3BPPP/5RK1 b - - c0 "After move Rd5 has been made.";
1k5r/pb3p1p/1q2rp1b/2pR4/1pQ1P3/1P3N2/P3BPPP/5RK1 b - - bm Rd5;

[User923005]

Oops. Make that:
r5k1/ppnqp2p/3p2p1/2pP4/P1P2r1P/6P1/1P3PK1/R2Q1R2 w - - c0 "After move Rxf4 has been made.";
r4rk1/ppnqp2p/3p2p1/2pP4/P1P2B1P/6P1/1P3PK1/R2Q1R2 b - - bm Rxf4;
r1r3k1/1bq2pp1/p4n1p/1p2pB2/PP3n2/2P2N2/1BQ2PPP/R3R1K1 w - - c0 "After move Nf4 has been made.";
r1r3k1/1bq2pp1/p4n1p/1p1npB2/PP6/2P2N2/1BQ2PPP/R3R1K1 b - - bm Nf4;
r1b2rk1/pp3pb1/3q2pp/2nP4/3R2P1/2P2N2/P1Q1BPP1/2B2RK1 b - - c0 "After move Rd4 has been made.";
r1b2rk1/pp3pb1/3q2pp/2nP4/6P1/2P2N2/P1Q1BPP1/2BR1RK1 w - - bm Rd4;
6k1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1Br1Q/2P2PP1/R3K3 w Q - c0 "After move Rxf3 has been made.";
5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - bm Rxf3;
3rrnk1/p1n1qpp1/1p5p/2p1P3/2P4P/1P2Q1PB/PB5K/3RR3 b - - c0 "After move Red1 has been made.";
3rrnk1/p1n1qpp1/1p5p/2pRP3/2P4P/1P2Q1PB/PB5K/4R3 w - - bm Red1;
2r1rbk1/p1qn2p1/3R1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1B2BK1 b - - c0 "After move Rxd6 has been made.";
2r1rbk1/p1qn2p1/3n1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1BR1BK1 w - - bm Rxd6;
1k5r/pb3p1p/1q2rp1b/2pR4/1pQ1P3/1P3N2/P3BPPP/5RK1 b - - c0 "After move Rd5 has been made.";
1k5r/pb3p1p/1q2rp1b/2p5/1pQ1P3/1P3N2/P3BPPP/3R1RK1 w - - bm Rd5;

[Jeremy Bernstein]

OK, wait a sec:

5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - bm Rxb5; c0 Ionov-Sergienko, 1999, RUS-chT; ce 0; id Monkey 06: Der Spekulative (The Speculative);

5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q -
This is Monkey #6, Der Spekulative. The "best move" is ...Rxb5? Because I neither see a rook which can reach b5, nor a piece that can be captured there. So there's something wrong with that position. The other positions all appear to work wrt their solutions, though.

jb

EDIT: here's a different epd, from the horse's mouth: http://www.mysnip.de/forum-archiv/thema ... nkeys.html. Only the 6th monkey got corrupted over time and space.

1k5r/pb3p1p/1q2rp1b/2p5/1pQ1P3/1P3N2/P3BPPP/3R1RK1 w - - bm Rd5;
r4rk1/ppnqp2p/3p2p1/2pP4/P1P2B1P/6P1/1P3PK1/R2Q1R2 b - - bm Rxf4;
3r1rk1/1Qp1q2p/4p3/p7/Pn1b1p1P/2N3P1/1P3PB1/2RR2K1 w - - bm Rxd4;
r2br1k1/1q3ppp/p2B4/Pp1pN3/3Pb1P1/1QP2P2/7P/R3R1K1 b - - bm Rxe5;
8/3r4/p5kp/Pb1R4/1P1B2P1/6P1/3K4/8 w - - bm Rxb5;
5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - bm Rxf3;
3rrnk1/p1n1qpp1/1p5p/2pRP3/2P4P/1P2Q1PB/PB5K/4R3 w - - bm Red1;
2nqr1k1/5p2/1p4pp/pP1rNn2/P4P2/BQ1p4/6PP/2RR2K1 b - - bm Rdxe5;
r1b2rk1/pp3pb1/3q2pp/2nP4/6P1/2P2N2/P1Q1BPP1/2BR1RK1 w - - bm Rd4;
2r1rbk1/p1qn2p1/3n1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1BR1BK1 w - - bm Rxd6;
r1r3k1/1bq2pp1/p4n1p/1p1npB2/PP6/2P2N2/1BQ2PPP/R3R1K1 b - - bm Nf4;
2q2rk1/2p2pb1/PpP1p1pp/2n5/5B1P/3Q2P1/4PPN1/2R3K1 w - - bm Rxc5;

[BB+]

A pictorial view -- note that the given Ionov-Sergienko best move (Rxb5) is garbage (probably copied from #5):[Event "Linares 1993"]
[White "Karpov"]
[Black "Gelfand"]
[FEN "1k5r/pb3p1p/1q2rp1b/2p5/1pQ1P3/1P3N2/P3BPPP/3R1RK1 w - - 0 1"]
[Setup "1"]
[Result "*"]
1. Rd5 *


[Event "Oakham 2001"]
[White "Tyomkin"]
[Black "MacDonald"]
[FEN "r4rk1/ppnqp2p/3p2p1/2pP4/P1P2B1P/6P1/1P3PK1/R2Q1R2 b - - 0 1"]
[Setup "1"]
[Result "*"]
1... Rxf4 *

[Event "Nordic 1997"]
[White "Akesson"]
[Black "Stefansson"]
[FEN "3r1rk1/1Qp1q2p/4p3/p7/Pn1b1p1P/2N3P1/1P3PB1/2RR2K1 w - - 0 1"]
[Setup "1"]
[Result "*"]
1. Rxd4 *

[Event "CHN-RUS 2001"]
[White "Peng"]
[Black "Motylev"]
[FEN "r2br1k1/1q3ppp/p2B4/Pp1pN3/3Pb1P1/1QP2P2/7P/R3R1K1 b - - 0 1"]
[Setup "1"]
[Result "*"]
1... Rxe5 *

[Event "2001"]
[White "Romanishin"]
[Black "Smagin"]
[FEN "8/3r4/p5kp/Pb1R4/1P1B2P1/6P1/3K4/8 w - - 0 1"]
[Setup "1"]
[Result "*"]
1. Rxb5 *

[Event "RUS Teams 1999"]
[White "Ionov"]
[Black "Sergienko"]
[FEN "5rk1/ppqb2pp/2n1p3/3pP3/2pP4/P1P1BN1Q/2P2PP1/R3K3 b Q - 0 1"]
[Setup "1"]
[Result "*"]
1... Rxb5 *

[Event "EU Teams 1999"]
[White "Movsesian"]
[Black "Sokolov"]
[FEN "3rrnk1/p1n1qpp1/1p5p/2pRP3/2P4P/1P2Q1PB/PB5K/4R3 w - - 0 1"]
[Setup "1"]
[Result "*"]
1. Red1 *

[Event "Reykjavik 1998"]
[White "Mortensen"]
[Black "Van der Weide"]
[FEN "2nqr1k1/5p2/1p4pp/pP1rNn2/P4P2/BQ1p4/6PP/2RR2K1 b - - 0 1"]
[Setup "1"]
[Result "*"]
1... Rdxe5 *

[Event "Chigorin 1997"]
[White "Zakharevich"]
[Black "Guliev"]
[FEN "r1b2rk1/pp3pb1/3q2pp/2nP4/6P1/2P2N2/P1Q1BPP1/2BR1RK1 w - - 0 1"]
[Setup "1"]
[Result "*"]
1. Rd4 *

[Event "Anibal 2000"]
[White "Minasian"]
[Black "Jonkman"]
[FEN "2r1rbk1/p1qn2p1/3n1pp1/P1p1p3/1p2P1P1/1N3Q1P/1PP2P2/R1BR1BK1 w - - 0 1"]
[Setup "1"]
[Result "*"]
1. Rxd6 *

[Event "Kiev 2000"]
[White "Svetushkin"]
[Black "Kruppa"]
[FEN "r1r3k1/1bq2pp1/p4n1p/1p1npB2/PP6/2P2N2/1BQ2PPP/R3R1K1 b - - 0 1"]
[Setup "1"]
[Result "*"]
1... Nf4 *

[Event "Geller 1999"]
[White "Dolinskij"]
[Black "Tosic"]
[FEN "2q2rk1/2p2pb1/PpP1p1pp/2n5/5B1P/3Q2P1/4PPN1/2R3K1 w - - 0 1"]
[Setup "1"]
[Result "*"]
1. Rxc5 *