h#7.5
8/7k/8/1q6/K7/8/Pr6/8 w - - 0 1
- Ka3 Qb3+ axb3 Kg6 b4 Kf5 b5 Ke4 b6 Kd3 b7 Kc2 b8=Q Kb1 Qxb2#
promotion excelsior excelsior:white
Note: the side to move is in check in the diagram.
KPvkqr
5 pieces.
- h#8.5
- longest mate
- h#7.5
- deepest unique
- 40
- positions at that depth
- h#7.5
- deepest dual
- h#6.5
- deepest strict dual
- 454,195,404
- positions with a helpmate
- 6,037,209
- with a unique solution
- 355,074,048
- cells in the plane
- 263,316,178 bytes
- on disk
Deepest unique problems
h#7.5
8/7k/8/8/5r2/8/q5P1/K7 w - - 0 1
- Kxa2 Kg6 Ka3 Kf5 g4+ Ke4 g5 Kd3 g6 Kc2 g7 Kb1 g8=Q Ka1 Qa2#
promotion excelsior excelsior:white single-piece single-piece:black
Note: the side to move is in check in the diagram; the solution begins with a capture.
Deepest dual problems
Deepest dual with different first and last moves: h#6.5. The deepest dual overall is h#7.5, where the two solutions share a first or a last move.
h#6.5
8/8/8/4k3/3r4/3P3q/8/K7 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kb1 Ra4 d4+ Kd6 d5 Kc5 d6 Qc8 d7 Kb4 dxc8=Q Ka3 Qc3#
- Ka2 Rb4 d4+ Kd6 d5 Kc5 d6 Qc8 d7 Kb5 dxc8=Q Ka4 Qa6#
h#6.5
8/8/8/8/6qk/8/1r5P/1K6 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ka1 Kg5 h4+ Kf4 h5 Ke3 h6 Kd2 h7 Kc1 h8=Q Qd1 Qxb2#
- Kc1 Qg5+ Kd1 Kg4 h4 Rb6 h5 Rg6 h6 Kh5 h7 Kh6 h8=Q#
pure model promotion excelsior excelsior:white self-block umnov
Note: the side to move is in check in the diagram.
h#6.5
8/8/8/8/K5qk/1r6/7P/8 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ka5 Qg5+ Ka4 Kg4 h4 Rb6 h5 Rg6 h6 Kh5 h7 Kh6 h8=Q#
- Kxb3 Kg5 h4+ Kf4 h5 Ke3 h6 Kd2 h7 Kc1 h8=Q Kb1 Qb2#
pure model promotion excelsior excelsior:white switchback self-block single-piece single-piece:black umnov
Note: the side to move is in check in the diagram.