h#6
7Q/7k/8/6R1/p7/8/8/K7 b - - 0 1
- Kxh8 Kb2 a3+ Kc3 a2 Kd4 a1=R Ke5 Ra8 Kf6 Rg8 Rh5#
pure model ideal promotion underpromotion self-block kniest
Note: the side to move is in check in the diagram; the solution begins with a capture.
KQRvkp
5 pieces.
- h#7
- longest mate
- h#6
- deepest unique
- 72
- positions at that depth
- h#6
- deepest dual
- h#4
- deepest strict dual
- 458,967,310
- positions with a helpmate
- 54,354,776
- with a unique solution
- 355,074,048
- cells in the plane
- 266,527,150 bytes
- on disk
Deepest unique problems
h#6
K7/8/8/8/1p6/4R3/8/5kQ1 b - - 0 1
- Kxg1 Kb7 b3 Kc6 b2 Kd5 b1=R Ke4 Rb2 Kf3 Rh2 Re1#
pure model ideal promotion underpromotion switchback self-block kniest nocheck
Note: the side to move is in check in the diagram; the solution begins with a capture.
h#6
8/7Q/6Rk/8/8/1p6/8/K7 b - - 0 1
- Kxh7 Kb2 Kh8 Kc3 b2 Kd4 b1=R Ke5 Rb8 Kf6 Rg8 Rh6#
pure model ideal promotion underpromotion self-block nocheck umnov
Note: the diagram has no legal last move, so it cannot arise in a game.
Deepest dual problems
Deepest dual with different first and last moves: h#4. The deepest dual overall is h#6, where the two solutions share a first or a last move.
Only one distinct idea exists at this depth: 2 positions share a solution.
h#4
3R4/4kQ2/8/8/2p5/8/2K5/8 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kxf7 Kd2 Kg6 Ke3 Kh5 Kf4 Kh4 Rh8#
- Kxd8 Qe8+ Kc7 Kc3 Kb6 Kxc4 Ka5 Qb5#
pure model mirror single-piece single-piece:black zilahi
Note: the side to move is in check in the diagram; the solution begins with a capture.