h#8.5
8/8/N7/7k/b1b5/8/8/K7 w - - 0 1
- Kb2 Kg4 Ka3 Kf3 Kxa4 Ke2 Kb4 Kd1 Kc3 Kc1 Nb4 Kb1 Kd2 Ka1 Kc1 Ba2 Nc2#
KNvkbb
5 pieces.
- h#10.5
- longest mate
- h#8.5
- deepest unique
- 69
- positions at that depth
- h#8.5
- deepest dual
- h#7
- deepest strict dual
- 85,404,228
- positions with a helpmate
- 369,966
- with a unique solution
- 121,110,528
- cells in the plane
- 34,395,069 bytes
- on disk
Deepest unique problems
h#8.5
8/8/7k/8/8/3b4/8/NK1b4 w - - 0 1
- Kc1 Kg5 Kxd1 Kf4 Kc1 Ke3 Kb2 Kd2 Kb3 Kc1 Nc2 Kb1 Nd4 Ka1 Ka3 Bb1 Nb3#
pure model ideal switchback self-block nocheck
Note: the side to move is in check in the diagram.
h#8.5
7k/8/8/8/8/1b2b3/N7/1K6 w - - 0 1
- Kb2 Kg7 Kc3 Kf6 Kd3 Ke5 Ke2 Kd4 Nb4 Kc3 Kxe3 Kb2 Kd2 Ka1 Kc1 Ba2 Nc2#
Deepest dual problems
Deepest dual with different first and last moves: h#7. The deepest dual overall is h#8.5, where the two solutions share a first or a last move.
Only one position exists at this depth.
h#7
8/8/5k2/8/3K4/3b4/2b5/3N4 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Bb3 Kxd3 Ke5 Ke2 Kd4 Ne3 Kc3 Ke1 Kb2 Kd2 Ka1 Kc1 Ba2 Nc2#
- Bc4 Ke3 Ke5 Kf2 Kd4 Ne3 Kc3 Ke1 Kb2 Kd2 Ka1 Kc1 Ba2 Nxc2#