h#6
5k2/8/8/8/8/3K3N/N7/7N b - - 0 1
- Kg7 Ke4 Kh6 Kf5 Kh5 Ng3+ Kh4 Kg6 Kg4 Nf2+ Kh4 Nf5#
pure mirror switchback single-piece single-piece:black nocapture
KNNNvk
5 pieces.
- h#8
- longest mate
- h#6
- deepest unique
- 4
- positions at that depth
- h#6
- deepest dual
- h#5
- deepest strict dual
- 30,239,918
- positions with a helpmate
- 753,275
- with a unique solution
- 121,110,528
- cells in the plane
- 28,184,883 bytes
- on disk
Deepest unique problems
Only one distinct idea exists at this depth: 4 positions share a solution.
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
7N/4k1N1/8/8/8/8/8/2K4N b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kf6 Kd2 Kg5 Ke3 Kh4 Kf4 Kh3 Nf2+ Kh4 Ng6#
- Kf8 Kd2 Kg8 Ke3 Kh7 Kf4 Kh6 Nf5+ Kh5 Nhg3#
pure model ideal mirror switchback single-piece single-piece:black nocapture
h#5
8/7N/8/8/8/8/k7/2NK3N b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kb2 Nb3 Kc3 Kc1 Kd3 Nc5+ Ke2 Ng3+ Ke1 Nd3#
- Ka3 Kc2 Kb4 Kb1 Kc3 Ng5 Kd2 Nf3+ Kd1 Nf2#
pure model ideal mirror single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.
h#5
8/6k1/8/4N3/2N5/8/3K4/3N4 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kh6 Ke3 Kh5 Kf4 Kh4 Nce3 Kh3 Nf2+ Kh2 Nf3#
- Kh7 Ke3 Kh6 Kf4 Kh5 Nce3 Kh4 Nf3+ Kh3 Nf2#
set-play pure model ideal mirror single-piece single-piece:black nocapture