h#6
7k/8/8/6Q1/8/8/1n6/K7 b - - 0 1
- Kh7 Kxb2 Kh8 Kc3 Kh7 Kd4 Kh8 Ke5 Kh7 Kf6 Kh8 Qg7#
set-play pure model ideal switchback single-piece single-piece:black pendulum nocheck
KQvkn
4 pieces.
- h#7
- longest mate
- h#6
- deepest unique
- 4
- positions at that depth
- h#5.5
- deepest dual
- h#4.5
- deepest strict dual
- 2,668,586
- positions with a helpmate
- 140,581
- with a unique solution
- 1,892,352
- cells in the plane
- 1,778,583 bytes
- on disk
Deepest unique problems
Only 2 distinct ideas exist at this depth.
h#6
8/8/7k/6Q1/8/2n5/8/K7 b - - 0 1
- Kh7 Kb2 Kh8 Kxc3 Kh7 Kd4 Kh8 Ke5 Kh7 Kf6 Kh8 Qg7#
pure model ideal switchback single-piece single-piece:black nocheck
Note: the side to move is in check in the diagram.
Deepest dual problems
Deepest dual with different first and last moves: h#4.5. The deepest dual overall is h#5.5, where the two solutions share a first or a last move.
Only 2 distinct ideas exist at this depth.
h#4.5
4k3/8/8/8/4n3/8/8/2KQ4 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Qg1 Ng5 Kd2 Kf7 Ke3 Kg6 Kf4 Kh5 Qxg5#
- Qd2 Kf7 Kd1 Kg6 Ke2 Kh5 Kf3 Kh4 Qh6#
h#4.5
8/8/7k/5Q2/8/2n5/1K6/8 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kc2 Ne4 Kd3 Ng5 Ke3 Kh5 Kf4 Kh4 Qg4#
- Kxc3 Kg7 Kd4 Kh8 Ke5 Kg8 Kf6 Kf8 Qc8#
pure model ideal mirror single-piece single-piece:black nocheck