h#6
K7/8/2p5/1q6/8/8/8/5Qk1 b - - 0 1
- Kh2 Qf7 Kg3 Qb7 Kf4 Kb8 Ke5 Kc8 Kd6 Kd8 Qd5 Qe7#
Note: the side to move is in check in the diagram.
KQvkqp
5 pieces.
- h#7
- longest mate
- h#6
- deepest unique
- 4
- positions at that depth
- h#6
- deepest dual
- h#5
- deepest strict dual
- 401,887,090
- positions with a helpmate
- 18,384,559
- with a unique solution
- 355,074,048
- cells in the plane
- 282,883,162 bytes
- on disk
Deepest unique problems
Only 2 distinct ideas exist at this depth.
h#6
K7/3q4/2p5/8/8/7Q/8/7k b - - 0 1
- Kg1 Qb3 Kf2 Qb7 Ke3 Ka7 Kd4 Ka6 Kc5 Ka5 Qd5 Qb4#
Note: the side to move is in check in the diagram.
Deepest dual problems
Deepest dual with different first and last moves: h#5. The deepest dual overall is h#6, where the two solutions share a first or a last move.
h#5
8/8/8/6k1/3p1Q2/8/6q1/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kh5 Qe5+ Kg4 Kb1 Kf3 Kc1 Kf2 Kd1 Kf1 Qe1#
- Kg6 Qb8 Kf5 Kb1 Ke4 Kc1 Kd3 Kd1 Qe4 Qb3#
self-block single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.
h#5
7q/8/7k/8/8/2p1Q3/8/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kh5 Kb1 Kg4 Qg5+ Kf3 Kc2 Kf2 Kd3 Ke1 Qg1#
- Kg6 Kb1 Kf5 Qf2+ Ke4 Kc1 Kd3 Kd1 Qd4 Qe2#
pure model mirror self-block single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.
h#5
8/1q2k3/3Q4/8/3p4/8/8/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kf7 Qh2 Ke6 Ka2 Kd5 Ka3 Kc4 Ka4 Qd5 Qc2#
- Ke8 Qe5+ Kd7 Ka2 Kc6 Ka3 Kb6 Ka4 Ka6 Qa5#
self-block single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.