h#5
8/8/8/8/6kB/1r3Q2/8/K7 b - - 0 1
- Kxh4 Qxb3 Kg4 Qa2 Kf3 Kb2 Ke2 Kc3+ Kd1 Qd2#
switchback single-piece single-piece:black
Note: the side to move is in check in the diagram; the solution begins with a capture.
KQBvkr
5 pieces.
- h#6
- longest mate
- h#5
- deepest unique
- 15
- positions at that depth
- h#5
- deepest dual
- h#3
- deepest strict dual
- 139,052,004
- positions with a helpmate
- 16,559,884
- with a unique solution
- 121,110,528
- cells in the plane
- 110,098,514 bytes
- on disk
Deepest unique problems
h#5
8/7Q/6k1/6B1/1r6/8/8/K7 b - - 0 1
- Kxg5 Ka2 Kf4 Ka3 Ke3 Kxb4 Kd2 Kb3 Kc1 Qc2#
single-piece single-piece:black nocheck
Note: the side to move is in check in the diagram; the solution begins with a capture.
h#5
8/8/8/6B1/6k1/5r1Q/8/1K6 b - - 0 1
- Kxg5 Qxf3 Kh4 Qh5+ Kg3 Kc2 Kf2 Kd3 Ke1 Qe2#
single-piece single-piece:black
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#3. The deepest dual overall is h#5, where the two solutions share a first or a last move.
h#3
8/8/8/8/3k4/2Q5/5r2/K1B5 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke4 Kb1 Rf5 Kc2 Re5 Qd3#
- Kd5 Qa5+ Kc4 Bd2 Kb3 Qa2#
self-block single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.
h#3
8/6r1/8/8/3k4/2Q4B/8/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke4 Qe1+ Kd3 Ka2 Kc2 Bf5#
- Kd5 Qa5+ Kc4 Kb1 Kb3 Be6#
mirror single-piece single-piece:black nocapture
Note: the side to move is in check in the diagram.
h#3
8/8/8/8/3k3B/2Q5/3r4/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke4 Qb4+ Kd3 Bf6 Kc2 Qb1#
- Kd5 Qxd2+ Kc4 Be1 Kb3 Qa2#
single-piece single-piece:black
Note: the side to move is in check in the diagram.