h#6
5k2/4R3/7N/8/6N1/8/2K5/8 b - - 0 1
- Kxe7 Nf2 Kf6 Kd3 Kg5 Ke4 Kh4 Kf5 Kg3 Kg6 Kh4 Nf5#
pure model ideal mirror switchback single-piece single-piece:black nocheck
Note: the solution begins with a capture.
KRNNvk
5 pieces.
- h#8
- longest mate
- h#6
- deepest unique
- 27
- positions at that depth
- h#6
- deepest dual
- h#4.5
- deepest strict dual
- 85,464,174
- positions with a helpmate
- 10,096,000
- with a unique solution
- 121,110,528
- cells in the plane
- 71,906,038 bytes
- on disk
Deepest unique problems
h#6
8/8/8/8/8/8/k1K5/R1N4N b - - 0 1
- Kxa1 Kd1 Kb2 Nb3 Kc3 Kc1 Kd3 Nc5+ Ke2 Ng3+ Ke1 Nd3#
pure model ideal mirror single-piece single-piece:black
Note: the diagram has no legal last move, so it cannot arise in a game.
h#6
k7/1R6/8/8/8/8/N2K4/5N2 b - - 0 1
- Kxb7 Kc3 Kc6 Kb4 Kd5 Ka5 Kc4 Ne3+ Kb3 Nc1+ Ka3 Nc4#
pure model ideal mirror single-piece single-piece:black
Note: the solution begins with a capture.
Deepest dual problems
Deepest dual with different first and last moves: h#4.5. 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#4.5
4k3/8/8/8/2R5/8/8/NK4N1 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Nc2 Kf7 Ne1 Kg6 Rg4+ Kh5 Rg5+ Kh4 Nef3#
- Nb3 Kf7 Nd2 Kg6 Rg4+ Kh5 Rg5+ Kh4 Ndf3#