The longest mate is 1090 half-moves QN4n1/8/3k4/8/b1K5/8/8/6r1 b - - Rg1g4 Kc4c3 Ng8e7 Qa8a6 Ba4c6 Qa6a3 Kd6e6 Kc3b2 Rg4g2 Kb2c1 Rg2g1 Kc1d2 Rg1g2 Kd2e1 Rg2g1 Ke1f2 Rg1g2 Kf2f1 Rg2g5 Qa3a6 Rg5f5 Kf1g1 Rf5g5 Kg1h2 Rg5h5 Kh2g3 Rh5c5 Kg3h3 Rc5c3 Kh3h2 Ke6d6 Qa6a7 Ne7d5 Nb8a6 Rc3c2 Kh2g1 Rc2c4 Qa7b8 Kd6e6 Kg1h2 Nd5f6 Na6b4 Bc6e4 Qb8b6 Ke6e5 Qb6b5 Ke5d4 Kh2g1 Nf6g4 Qb5d7 Kd4e3 Qd7a7 Ke3d2 Qa7a2 Kd2c3 Qa2a3 Kc3d4 Qa3b2 Kd4e3 Qb2b3 Ke3d4 Qb3d1 Kd4e3 Qd1e1 Ke3d4 Qe1d2 Kd4e5 Kg1f1 Ke5e6 Kf1e2 Ng4e5 Qd2a2 Ke6f6 Qa2a6 Be4c6 Qa6b6 Kf6f5 Qb6b8 Bc6f3 Ke2d2 Bf3e4 Kd2e3 Kf5f6 Ke3e2 Kf6f5 Qb8f8 Kf5e6 Nb4a6 Be4f3 Ke2d2 Rc4d4 Kd2c2 Rd4c4 Kc2b1 Bf3e4 Kb1a2 Ne5d3 Qf8e8 Ke6f6 Qe8d8 Kf6f5 Na6c7 Rc4c2 Ka2a3 Rc2c3 Ka3a4 Rc3c5 Nc7a6 Rc5c1 Qd8d6 Kf5g4 Ka4a5 Kg4f3 Qd6f8 Kf3e3 Ka5b6 Rc1c2 Qf8h8 Ke3f3 Qh8a1 Kf3e3 Kb6a7 Rc2c1 Qa1a2 Ke3f3 Ka7b8 Rc1c6 Qa2a3 Kf3e3 Qa3a1 Ke3f4 Qa1a5 Rc6c2 Qa5a3 Rc2c6 Kb8a7 Rc6c1 Qa3b3 Rc1c6 Qb3b8 Kf4f3 Qb8d8 Kf3e2 Qd8g5 Ke2f2 Qg5d2 Kf2f3 Qd2a5 Rc6c1 Qa5b6 Rc1c6 Qb6d4 Kf3f4 Qd4d8 Kf4e3 Na6b8 Rc6c1 Nb8d7 Rc1a1 Ka7b6 Ra1b1 Kb6c7 Rb1c1 Kc7d6 Rc1c6 Kd6e7 Be4f5 Nd7f6 Nd3e5 Nf6e8 Rc6e6 Ke7f8 Ne5d7 Kf8f7 Nd7e5 Kf7g7 Re6g6 Kg7f8 Ne5d7 Kf8e7 Nd7e5 Qd8d1 Rg6e6 Ke7f8 Bf5d3 Qd1e1 Ke3d4 Qe1f2 Kd4e4 Qf2h4 Ke4d5 Qh4a4 Kd5c5 Qa4a3 Kc5d4 Ne8c7 Re6f6 Kf8e8 Kd4e4 Ke8d8 Rf6f7 Kd8c8 Bd3c4 Qa3d6 Rf7h7 Qd6d2 Ke4f5 Kc8b8 Kf5g4 Qd2f2 Rh7f7 Qf2h2 Kg4f5 Qh2h6 Rf7f6 Qh6h7 Kf5f4 Kb8b7 Rf6f7 Qh7h6 Kf4e4 Kb7c8 Bc4e2 Qh6c1 Be2f3 Kc8b7 Rf7f6 Kb7b8 Ne5c6 Kb8c8 Rf6f8 Kc8b7 Nc6d4 Qc1g5 Ke4d3 Kb7a7 Rf8f7 Qg5g6 Rf7f5 Qg6d6 Kd3c4 Qd6a6 Kc4c3 Qa6a3 Kc3d2 Ka7b8 Rf5f6 Kb8c8 Bf3g4 Kc8b7 Bg4f3 Kb7b8 Rf6c6 Qa3a4 Kd2e3 Nc7e8 Ke3e4 Qa4a8 Ke4e5 Qa8a5 Ke5e4 Qa5g5 Ke4d3 Qg5g3 Kd3c3 Ne8d6 Kc3d3 Qg3h2 Rc6c3 Qh2f2 Bf3d5 Qf2g1 Bd5f3 Qg1f1 Kd3e3 Nd6c4 Ke3f4 Nc4b2 Rc3c2 Nb2a4 Rc2b2 Kb8c7 Rb2c2 Kc7b6 Rc2c6 Kb6a5 Kf4e4 Qf1f2 Ke4d3 Qf2g1 Bf3e2 Na4b6 Nd4b3 Ka5a6 Be2f3 Qg1f1 Kd3e3 Qf1b1 Nb3d4 Ka6a7 Rc6e6 Ka7b8 Re6e8 Kb8c7 Re8e7 Kc7d6 Re7e6 Kd6d7 Bf3c6 Kd7d8 Re6e8 Kd8c7 Re8e7 Kc7d6 Re7e6 Kd6c5 Re6e5 Kc5c4 Bc6b5 Kc4b4 Ke3d2 Qb1h7 Bb5e2 Qh7d7 Kd2d3 Nb6a4 Re5b5 Kb4a3 Rb5b3 Ka3a2 Rb3b4 Qd7h3 Be2f3 Qh3h7 Kd3d2 Na4b2 Bf3d5 Ka2b1 Nd4e2 Qh7c2 Kd2e1 Kb1a1 Bd5e4 Qc2d1 Ke1f2 Qd1d2 Rb4d4 Qd2a5 Rd4d5 Qa5b4 Rd5d4 Qb4c5 Kf2e1 Nb2c4 Be4d5 Qc5a5 Ke1f2 Nc4b6 Bd5c6 Ka1b2 Bc6b5 Qa5a7 Kf2e1 Qa7a8 Bb5d3 Qa8a5 Ke1f2 Qa5c5 Kf2e1 Nb6d5 Rd4c4 Qc5e7 Bd3e4 Nd5b4 Ke1d1 Kb2b3 Be4d3 Qe7f8 Kd1e1 Qf8e8 Ke1d1 Kb3a3 Kd1e1 Qe8e6 Rc4c3 Ka3a4 Rc3c4 Qe6e3 Rc4d4 Ka4a5 Bd3e4 Qe3h3 Ke1d2 Qh3e6 Kd2e1 Nb4a6 Be4c2 Ka5b6 Rd4f4 Qe6d5 Bc2g6 Qd5b3 Ke1f1 Na6c7 Kf1f2 Kb6a7 Rf4b4 Qb3h3 Bg6f7 Nc7a6 Rb4f4 Qh3h2 Kf2e1 Qh2h1 Ke1d2 Qh1h6 Kd2d1 Qh6g7 Bf7d5 Qg7a1 Kd1d2 Qa1a5 Ne2c3 Ka7b8 Rf4c4 Qa5a3 Nc3e2 Na6c7 Bd5e4 Qa3a2 Kd2d3 Qa2b3 Rc4c3 Qb3b5 Rc3c4 Nc7e6 Kd3c3 Qb5g5 Kc3c2 Qg5e3 Rc4b4 Kb8a7 Ne2c3 Ne6c5 Nc3b5 Ka7b6 Nb5c3 Kb6a6 Rb4b6 Ka6a7 Rb6b4 Qe3e1 Be4d3 Qe1f2 Nc3e2 Qf2f3 Rb4c4 Ka7b6 Rc4b4 Kb6c7 Rb4c4 Qf3e3 Ne2c1 Kc7c6 Rc4c3 Kc6d6 Rc3c4 Kd6e6 Rc4b4 Ke6f6 Rb4c4 Kf6g5 Rc4b4 Qe3f2 Nc1e2 Qf2f3 Ne2c1 Qf3d5 Kc2c3 Qd5e5 Kc3d2 Qe5d6 Kd2c3 Qd6e7 Kc3c2 Qe7d8 Kc2c3 Nc5e6 Rb4b5 Kg5h6 Nc1b3 Ne6c7 Rb5c5 Nc7d5 Kc3b2 Nd5e3 Rc5c6 Kh6g7 Bd3b5 Qd8h8 Kb2a3 Qh8f8 Rc6c5 Qf8a8 Ka3b4 Qa8a2 Kb4c3 Kg7f6 Bb5d3 Qa2f2 Kc3b4 Qf2b2 Rc5h5 Kf6e7 Rh5h7 Ke7e8 Rh7h5 Ke8f8 Kb4a4 Qb2f6 Ka4b5 Qf6d6 Rh5h8 Kf8f7 Rh8h7 Kf7g8 Nb3c5 Ne3d5 Kb5c4 Nd5e7 Bd3e4 Ne7c8 Rh7h1 Qd6g3 Rh1f1 Nc8d6 Kc4d4 Nd6f7 Rf1f5 Qg3g1 Kd4d5 Qg1h2 Be4d3 Qh2d6 Kd5e4 Kg8g7 Bd3c4 Nf7d8 Ke4e3 Qd6c6 Ke3d2 Kg7h6 Kd2c3 Qc6g6 Rf5f3 Qg6d6 Nc5d3 Nd8b7 Rf3f5 Qd6a3 Bc4b3 Nb7a5 Rf5f6 Kh6g7 Rf6b6 Qa3e7 Rb6b5 Na5c6 Rb5d5 Qe7f8 Kc3c2 Qf8a3 Bb3c4 Qa3a4 Kc2c3 Kg7f6 Rd5c5 Qa4a8 Kc3d2 Nc6d4 Rc5d5 Qa8a1 Rd5c5 Qa1a4 Kd2c3 Nd4f3 Rc5d5 Qa4a1 Kc3b4 Nf3d4 Nd3c5 Qa1e1 Kb4a4 Nd4c2 Rd5d6 Kf6g5 Rd6d2 Qe1e8 Ka4b3 Nc2e3 Nc5e6 Kg5h6 Rd2e2 Qe8c6 Re2h2 Kh6g6 Bc4d3 Kg6f6 Rh2h6 Kf6e7 Rh6h7 Ke7d6 Ne6c7 Kd6e5 Nc7b5 Qc6d5 Kb3c3 Ke5f6 Rh7c7 Qd5f3 Nb5d4 Ne3d1 Kc3c2 Qf3f2 Nd4e2 Qf2b6 Rc7c8 Nd1e3 Kc2d2 Ne3g2 Rc8c3 Qb6b2 Bd3c2 Qb2b4 Bc2b3 Qb4a5 Kd2d3 Qa5b5 Kd3d2 Qb5g5 Kd2c2 Ng2e3 Kc2b2 Qg5e5 Kb2c1 Ne3g4 Bb3c4 Qe5c5 Kc1b2 Qc5b4 Kb2c2 Kf6g5 Ne2c1 Qb4c5 Kc2d2 Kg5f6 Nc1d3 Qc5a5 Bc4b3 Ng4h2 Kd2c2 Nh2f3 Kc2b2 Nf3d4 Nd3c5 Nd4b5 Rc3f3 Kf6e5 Bb3c2 Qa5b4 Nc5b3 Ke5d6 Rf3g3 Kd6d7 Rg3h3 Kd7d8 Rh3g3 Qb4a3 Kb2b1 Qa3e7 Rg3d3 Kd8e8 Nb3d2 Qe7b4 Kb1c1 Nb5c3 Bc2b3 Qb4c5 Bb3c4 Nc3e2 Kc1c2 Ne2d4 Kc2b2 Nd4c6 Bc4b3 Qc5e5 Rd3c3 Nc6d4 Bb3c4 Ke8f8 Nd2b1 Qe5h2 Kb2a1 Qh2f4 Nb1a3 Qf4d2 Na3b1 Qd2e1 Rc3d3 Nd4c6 Rd3c3 Nc6a5 Bc4d3 Qe1e7 Ka1b2 Qe7b7 Kb2c2 Na5c6 Kc2c1 Nc6d4 Bd3c4 Qb7b4 Bc4f1 Qb4b8 Bf1c4 Qb8f4 Kc1b2 Qf4f2 Kb2c1 Nd4f5 Bc4b3 Nf5e3 Rc3c8 Kf8e7 Rc8c3 Qf2e2 Rc3c7 Ke7d8 Rc7c3 Kd8d7 Bb3e6 Kd7e7 Be6b3 Ke7d8 Rc3c5 Qe2e1 Kc1b2 Qe1f2 Kb2a1 Ne3g4 Rc5c3 Qf2d4 Bb3c4 Kd8e7 Ka1b2 Ng4f2 Kb2b3 Qd4d1 Kb3b2 Qd1a4 Bc4b3 Qa4d4 Kb2c1 Nf2e4 Rc3c7 Ke7d8 Rc7c2 Qd4f6 Rc2c4 Qf6e5 Nb1a3 Ne4c5 Bb3c2 Kd8e7 Kc1b1 Qe5d6 Kb1b2 Qd6b6 Kb2a2 Ke7f6 Rc4c3 Qb6a5 Rc3c4 Kf6g5 Ka2b2 Qa5b6 Kb2c1 Nc5d7 Rc4c3 Qb6d4 Na3b1 Kg5f6 Rc3b3 Nd7e5 Nb1d2 Kf6g7 Bc2e4 Kg7f7 Rb3b7 Kf7f6 Rb7b3 Ne5g4 Be4c2 Kf6e7 Rb3d3 Qd4a1 Nd2b1 Qa1a7 Rd3c3 Qa7d4 Rc3c7 Ke7d8 Rc7c3 Ng4e5 Kc1b2 Kd8e7 Bc2b3 Ke7e8 Kb2c1 Ke8d8 Kc1b2 Kd8e7 Kb2c1 Ke7f6 Kc1b2 Qd4f4 Kb2a2 Qf4f2 Bb3c2 Qf2e2 Nb1a3 Qe2d2 Na3b1 Qd2d5 Bc2b3 Qd5g2 Bb3c2 Qg2b7 Nb1a3 Qb7b4 Rc3h3 Qb4c5 Ka2b2 Qc5b6 Rh3b3 Qb6d4 Kb2c1 Kf6f7 Rb3b7 Kf7e6 Kc1b1 Ke6f6 Rb7b3 Kf6g7 Na3b5 Qd4g1 Kb1a2 Kg7f8 Rb3c3 Qg1b6 Nb5a3 Qb6b4 Ka2a1 Kf8e7 Rc3h3 Qb4d4 Ka1b1 Ne5c6 Rh3d3 Qd4b6 Rd3b3 Nc6b4 Bc2h7 Qb6e6 Kb1b2 Qe6e5 Kb2b1 Ke7f8 Na3c2 Nb4d5 Rb3f3 Kf8g7 Bh7d3 Nd5c3 Kb1c1 Qe5d5 Rf3g3 Kg7f8 Nc2e1 Qd5h5 Rg3f3 Kf8g7 Kc1c2 Nc3d5 Rf3g3 Kg7h8 Rg3f3 Qh5h4 Kc2c1 Qh4h6 Kc1d1 Qh6g5 Bd3e4 Nd5e3 Kd1e2 Ne3c4 Rf3d3 Qg5f4 Be4f3 Kh8g7 Rd3d7 Kg7h6 Rd7d3 Qf4f6 Ke2f1 Qf6b2 Bf3d5 Nc4e5 Rd3h3 Kh6g7 Rh3g3 Kg7f8 Bd5e4 Qb2h2 Rg3g2 Qh2h1 Kf1e2 Qh1h4 Rg2f2 Kf8e8 Be4d3 Ke8e7 Rf2f1 Ke7d6 Rf1f2 Kd6c7 Ne1f3 Qh4h5 Bd3e4 Qh5g4 Ke2e3 Qg4g3 Rf2c2 Kc7b6 Rc2b2 Kb6a5 Be4d5 Ne5g4 Ke3d3 Qg3h3 Rb2e2 Qh3h1 Re2c2 Qh1f1 Kd3d2 Qf1f2 Kd2c1 Qf2e3 Kc1b1 Ng4f2 Nf3d2 Qe3e1 Kb1a2 Nf2d3 Nd2c4 Ka5b5 Nc4a3 Kb5b6 Na3c4 Kb6a7 Rc2d2 Qe1g3 Bd5g2 Nd3b4 Ka2b2 Nb4a6 Bg2f1 Na6c5 Rd2c2 Nc5a4 Kb2a2 Na4c3 Ka2b2 Nc3d5 Rc2c1 Ka7b8 Kb2c2 Qg3g1 Kc2b2 Qg1c5 Kb2c2 Kb8c7 Bf1e2 Qc5f2 Kc2d2 Kc7d7 Rc1f1 Qf2d4 Be2d3 Nd5f4 Rf1f3 Kd7e7 Rf3e3 Ke7f6 Nc4e5 Nf4d5 Re3e2 Qd4a4 Re2e4 Qa4a5 Kd2c2 Qa5c3 Kc2d1 Qc3b2 Kd1e1 Nd5c3 Ne5g4 Kf6g5 Re4d4 Qb2c1 Ke1f2 Qc1d2 Kf2f3 Qd2d1 Kf3f2 Nc3e4