h#9.5
8/k1B2p2/8/5n2/8/8/K7/8 w - - 0 1
- Kb3 Kb7 Kc4 Kc8 Kd5 Kd7 Ke5 Ke8 Kf6 Kf8 Bd6+ Kg8 Bf8 Kh8 Kxf7 Nh6+ Kg6 Ng8 Bg7#
KBvknp
5 pieces.
- h#15.5
- longest mate
- h#9.5
- deepest unique
- 2
- positions at that depth
- h#9.5
- deepest dual
- h#7
- deepest strict dual
- 542,127,993
- positions with a helpmate
- 1,662,371
- with a unique solution
- 355,074,048
- cells in the plane
- 149,123,829 bytes
- on disk
Deepest unique problems
Only one distinct idea exists at this depth: 2 positions share a solution.
Deepest dual problems
Deepest dual with different first and last moves: h#7. The deepest dual overall is h#9.5, where the two solutions share a first or a last move.
h#7
8/6k1/8/4B3/5p2/8/8/K2n4 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kh7 Kb1 f3 Kc2 f2 Kd3 f1=B+ Ke4 Bc4 Kf5 Bg8 Kf6 Kh8 Kg6#
- Kg8 Ka2 f3 Kb3 f2 Kc4 f1=B+ Kd5 Bd3 Ke6 Bh7 Kf6 Kh8 Kf7#
promotion underpromotion self-block single-piece single-piece:white nocapture
Note: the side to move is in check in the diagram.
h#7
8/8/8/4k3/7B/8/7p/1K5n b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Nf2 Bxf2 Kf6 Kc2 Kg7 Kd3 Kh8 Ke4 h1=B+ Kf5 Bd5 Kg6 Bg8 Bd4#
- Ng3 Bxg3+ Kf6 Kc2 Kg7 Kd3 Kh8 Ke4 h1=B+ Kf5 Bd5 Kg6 Bg8 Be5#
h#7
7k/1p6/1B6/8/8/1n6/K7/8 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Na5 Bxa5 b5 Kb3 b4 Kc4 b3 Kd5 b2 Ke6 b1=B Kf7 Bh7 Bc3#
- Nc5 Bxc5 b5 Kb3 b4 Kc4 b3 Kd5 b2 Ke6 b1=B Kf7 Bh7 Bd4#
set-play promotion underpromotion excelsior excelsior:black self-block nocheck umnov