h#7.5
8/6k1/8/8/2n5/b7/P7/K7 w - - 0 1
- Kb1 Bb4 a4 Kf6 a5 Ke5 a6 Kd4 a7 Kc3 a8=Q Kb3 Qg2 Ka3 Qa2#
set-play promotion excelsior excelsior:white closed-walk self-block nocapture nocheck
KPvkbn
5 pieces.
- h#9.5
- longest mate
- h#7.5
- deepest unique
- 1,222
- positions at that depth
- h#8
- deepest dual
- h#7.5
- deepest strict dual
- 544,931,667
- positions with a helpmate
- 5,595,709
- with a unique solution
- 355,074,048
- cells in the plane
- 218,197,806 bytes
- on disk
Deepest unique problems
h#7.5
4k3/6b1/8/8/8/2n5/2P5/K7 w - - 0 1
- Kb2 Nb5+ Ka2 Kd7 c4 Bc3 cxb5 Ba5 b6 Kc6 b7 Kb5 b8=Q+ Ka4 Qb3#
h#7.5
7k/6b1/8/8/8/8/1n1P4/K7 w - - 0 1
- d4 Kh7 Kxb2 Kg6 Ka3 Kf5 d5 Ke4 d6 Kd3 d7 Kc2 d8=Q Kb1 Qd1#
pure model mirror promotion excelsior excelsior:white single-piece single-piece:black nocheck
Chosen from the first 500 of 1,222 positions at this depth.
Deepest dual problems
Deepest dual with different first and last moves: h#7.5. The deepest dual overall is h#8, where the two solutions share a first or a last move.
h#7.5
8/7k/8/8/8/8/b5P1/1K2n3 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kb2 Kg6 Ka3 Kf5 g4+ Ke4 g5 Kd3 g6 Kc2 g7 Kb1 g8=Q Ka1 Qxa2#
- 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.
h#7.5
6k1/8/8/8/8/3b4/1K1P4/2n5 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kc3 Bc4 d3 Kf7 dxc4 Ke6 c5 Kd5 c6 Kc5 c7 Kb5 c8=Q Ka4 Qa6#
- Kxc1 Be4 d3 Kf7 dxe4 Ke6 e5 Kd5 e6 Kc4 e7 Kb3 e8=Q Ka2 Qa4#
pure model ideal mirror promotion excelsior excelsior:white nocheck umnov