h#6
6R1/8/7k/7p/7B/8/8/K7 b - - 0 1
- Kh7 Kb2 Kh6 Kc3 Kh7 Kd4 Kh6 Ke5 Kh7 Kf6 Kh6 Rh8#
switchback single-piece single-piece:black pendulum nocapture nocheck
KRBvkp
5 pieces.
- h#16
- longest mate
- h#6
- deepest unique
- 175
- positions at that depth
- h#7
- deepest dual
- h#5.5
- deepest strict dual
- 512,691,529
- positions with a helpmate
- 46,832,776
- with a unique solution
- 355,074,048
- cells in the plane
- 323,557,206 bytes
- on disk
Deepest unique problems
h#6
8/8/8/8/8/8/2pR4/K1k3B1 b - - 0 1
- Kxd2 Ka2 Kc1 Kb3 Kb1 Bc5 Ka1 Ba3 c1=N+ Kc2 Na2 Bb2#
pure model ideal promotion underpromotion switchback self-block umnov
Note: the solution begins with a capture.
h#6
8/8/1B6/8/k7/1R6/p7/K7 b - - 0 1
- Kxb3 Bd4 Kc4 Kb2 Kd3 Ka3 Kc2 Kb4 Kb1 Kc3 Ka1 Kc2#
single-piece single-piece:black nocheck
Note: the solution begins with a capture.
Deepest dual problems
Deepest dual with different first and last moves: h#5.5. The deepest dual overall is h#7, where the two solutions share a first or a last move.
Only one position exists at this depth.
h#5.5
K7/8/3p4/8/8/4B3/3R4/7k w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kb7 d5 Kc6 d4 Kd5 dxe3 Ke4 Kg1 Kf3 Kf1 Rd1#
- Rd3 Kg2 Kb7 Kf3 Ba7+ Ke4 Kb6 d5 Re3+ Kd4 Kb5#