h#6
7Q/7k/8/6Q1/8/8/8/K7 b - - 0 1
- Kxh8 Kb2 Kh7 Kc3 Kh8 Kd4 Kh7 Ke5 Kh8 Kf6 Kh7 Qg7#
switchback single-piece single-piece:black pendulum nocheck
Note: the side to move is in check in the diagram; the solution begins with a capture.
KQQvk
4 pieces.
- h#7
- longest mate
- h#6
- deepest unique
- 2
- positions at that depth
- h#5
- deepest dual
- h#2
- deepest strict dual
- 1,190,359
- positions with a helpmate
- 216,234
- with a unique solution
- 1,892,352
- cells in the plane
- 1,443,836 bytes
- on disk
Deepest unique problems
Only 2 distinct ideas exist at this depth.
h#6
7k/7Q/8/6Q1/8/8/8/K7 b - - 0 1
- Kxh7 Kb2 Kh8 Kc3 Kh7 Kd4 Kh8 Ke5 Kh7 Kf6 Kh8 Qg7#
pure model ideal switchback single-piece single-piece:black pendulum nocheck
Note: the side to move is in check in the diagram; the solution begins with a capture.
Deepest dual problems
Deepest dual with different first and last moves: h#2. The deepest dual overall is h#5, where the two solutions share a first or a last move.
h#2
8/8/8/8/8/8/Q1K5/1Q3k2 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kf2 Qa7+ Ke2 Qd1#
- Kg2 Qg8+ Kh3 Qh1#
mirror single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.
h#2
8/8/8/8/1Q5k/Q2K4/8/8 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kg3 Qh4+ Kf3 Qa8#
- Kg5 Qe4 Kf6 Qae7#
mirror single-piece single-piece:black nocapture umnov
Note: the side to move is in check in the diagram.
h#2
8/8/8/1Q5k/Q2K4/8/8/8 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kg4 Qd1+ Kf4 Qe5#
- Kg6 Qe5 Kf7 Qae8#
single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.