h#6
8/7k/5Q2/p4p2/8/8/8/K7 b - - 0 1
- a4 Kb2 a3+ Kc3 a2 Kd4 a1=R Ke5 Ra8 Kxf5 Rh8 Qg6#
pure model ideal promotion underpromotion self-block single-piece single-piece:black
KQvkpp
5 pieces.
- h#7
- longest mate
- h#6
- deepest unique
- 15
- positions at that depth
- h#6
- deepest dual
- h#5
- deepest strict dual
- 183,939,471
- positions with a helpmate
- 9,592,553
- with a unique solution
- 266,305,536
- cells in the plane
- 120,754,064 bytes
- on disk
Deepest unique problems
h#6
K7/8/5p2/2p5/8/5Q2/8/7k b - - 0 1
- Kh2 Kb7 c4 Kc6 c3 Kd5 c2 Ke4 c1=R Kf4 Rh1 Qg3#
pure model promotion underpromotion self-block nocapture nocheck
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
8/8/5k2/8/8/pp2Q3/8/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kf5 Qxb3 Ke4 Qe6+ Kd3 Ka2 Kd2 Kb3 Kc1 Qe1#
- a2 Qh6+ Ke5 Kb2 Kd4 Kc1 Kc3 Kd1 Kb2 Qc1#
pure model mirror self-block single-piece single-piece:black
h#5
8/5k2/2Q5/8/p7/p7/8/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke7 Qh1 Kd6 Kb1 Kc5 Kc2 Kb4 Kd3 Kb3 Qb1#
- a2 Qc1 Ke6 Kb2 Kd5 Kc2 Kc4 Kd2+ Kb3 Qc3#
h#5
5k2/2Q5/8/p7/p7/8/8/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke8 Qh2 Kd7 Kb2 Kc6 Kc3 Kb5 Kd4 Kb4 Qb2#
- a3 Qc1 Ke7 Kb1 Kd6 Kc2 Kc5 Kd3+ Kb4 Qc4#