h#3
8/8/8/8/4R3/3k4/2R5/K1Q5 b - - 0 1
- Kxe4 Kb2 Kd4 Qf4+ Kd3 Rd2#
closed-walk single-piece single-piece:black
Note: the solution begins with a capture.
KQRRvk
5 pieces.
- h#5
- longest mate
- h#3
- deepest unique
- 1,116
- positions at that depth
- h#3
- deepest dual
- h#2
- deepest strict dual
- 70,456,661
- positions with a helpmate
- 10,517,333
- with a unique solution
- 121,110,528
- cells in the plane
- 55,274,777 bytes
- on disk
Deepest unique problems
h#3
8/8/8/8/8/4R3/1RQk4/K7 b - - 0 1
- Kxe3 Ka2 Kd4 Qe4+ Kc3 Rc2#
single-piece single-piece:black
Note: the side to move is in check in the diagram; the solution begins with a capture.
h#3
8/8/8/8/8/4R3/3Rk1Q1/K7 b - - 0 1
- Kxe3 Re2+ Kd4 Kb2 Kd3 Qe4#
single-piece single-piece:black umnov
Note: the diagram has no legal last move, so it cannot arise in a game.
Chosen from the first 500 of 1,116 positions at this depth.
Deepest dual problems
Deepest dual with different first and last moves: h#2. The deepest dual overall is h#3, where the two solutions share a first or a last move.
h#2
8/8/8/2R5/1QR5/8/2k5/K7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kd1 Qb2 Ke1 Rc1#
- Kd3 Rc2 Ke3 R5c3#
pure model mirror single-piece single-piece:black nocapture nocheck umnov
Note: the side to move is in check in the diagram.
h#2
8/8/R7/8/R7/8/3k4/K1Q5 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke2 Re6+ Kd3 Re3#
- Kd3 Qd1+ Kc3 Rc6#
mirror single-piece single-piece:white single-piece:black nocapture
Note: the side to move is in check in the diagram.
h#2
8/8/8/8/R7/3R4/4k3/K3Q3 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kxe1 Ra2 Kf1 Rd1#
- Kxd3 Ra3+ Kc2 Rc3#
pure model mirror single-piece single-piece:white single-piece:black
Note: the side to move is in check in the diagram; the solution begins with a capture.