h#7
8/8/8/8/2p5/8/2Q5/K1k1B3 b - - 0 1
- Kxc2 Ka2 c3 Ka3 Kb1 Kb3 c2 Bb4 Ka1 Ba3 c1=N+ Kc2 Na2 Bb2#
pure model ideal promotion underpromotion self-block umnov
Note: the side to move is in check in the diagram; the solution begins with a capture.
KQBvkp
5 pieces.
- h#16
- longest mate
- h#7
- deepest unique
- 55
- positions at that depth
- h#8
- deepest dual
- h#3
- deepest strict dual
- 476,163,849
- positions with a helpmate
- 71,371,141
- with a unique solution
- 355,074,048
- cells in the plane
- 310,565,954 bytes
- on disk
Deepest unique problems
h#7
8/7p/8/4B3/8/kQ6/8/K7 b - - 0 1
- Kxb3 Kb1 Kc4 Kc2 Kd5 Kd3 Ke6 Ke4 Kf7 Kf5 Kg8 Kf6 Kh8 Kf7#
single-piece single-piece:white single-piece:black nocheck
Note: the side to move is in check in the diagram; the solution begins with a capture.
h#7
B7/8/8/1K6/3k4/4Qp2/8/8 b - - 0 1
- Kxe3 Kc4 f2 Bg2 f1=N Bh3 Kf2 Kd3 Kg1 Ke2 Kh1 Kf2 Nh2 Bg2#
pure model ideal promotion underpromotion switchback self-block nocheck
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#8, where the two solutions share a first or a last move.
h#3
7B/6p1/8/8/8/2k5/1Q6/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kd3 Qb3+ Kd2 Bxg7 Kc1 Bh6#
- Kc4 Qc2+ Kb4 Bxg7 Ka3 Bf8#
mirror single-piece single-piece:black
Note: the side to move is in check in the diagram.
h#3
8/8/8/p7/3k4/B1Q5/8/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke4 Qe1+ Kd3 Bb4 Kc2 Qb1#
- Kd5 Qxa5+ Kc4 Kb1 Kb3 Qb4#
single-piece single-piece:black
Note: the side to move is in check in the diagram.
h#3
8/8/8/8/3k4/2Q4B/4p3/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.