h#5
8/8/8/8/6Qk/N4R2/8/K7 b - - 0 1
- Kxg4 Rb3 Kf4 Rb2 Ke3 Nc2+ Kd2 Ne3+ Kc1 Rc2#
single-piece single-piece:black umnov
Note: the side to move is in check in the diagram; the solution begins with a capture.
KQRNvk
5 pieces.
- h#7
- longest mate
- h#5
- deepest unique
- 26
- positions at that depth
- h#5
- deepest dual
- h#3
- deepest strict dual
- 150,016,075
- positions with a helpmate
- 23,408,831
- with a unique solution
- 121,110,528
- cells in the plane
- 97,010,418 bytes
- on disk
Deepest unique problems
h#5
7N/8/8/7Q/7k/R7/8/K7 b - - 0 1
- Kxh5 Kb2 Kg4 Kc3 Kf3 Ng6 Ke2 Nf4+ Kd1 Ra1#
pure model ideal mirror single-piece single-piece:black
Note: the side to move is in check in the diagram; the solution begins with a capture.
h#5
8/N7/8/6Qk/R7/8/8/1K6 b - - 0 1
- Kxg5 Ra6 Kf4 Nb5 Ke3 Re6+ Kd2 Re2+ Kd1 Nc3#
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
8/3N4/8/8/8/8/2Q5/K2kR3 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kxe1 Qb1+ Kd2 Ne5 Kc3 Qb2#
- Kxc2 Re4 Kb3 Nc5+ Ka3 Ra4#
pure model ideal single-piece single-piece:black zilahi
Note: the diagram has no legal last move, so it cannot arise in a game.
h#3
8/N7/8/8/8/8/5R2/K2Qk3 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kxd1 Ka2 Kc1 Kb3 Kb1 Rf1#
- Kxf2 Nc6 Kg3 Ne5 Kh4 Qg4#
pure model mirror single-piece single-piece:black nocheck zilahi
Note: the side to move is in check in the diagram; the solution begins with a capture.
h#3
8/8/8/N7/8/8/4Q3/K4kR1 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kxg1 Nc4 Kh1 Ne3 Kg1 Qg2#
- Kxe2 Rg2+ Kd1 Rd2+ Kc1 Nb3#
switchback single-piece single-piece:black kniest
Note: the diagram has no legal last move, so it cannot arise in a game.