KRRvkn
5 pieces.
- h#7
- longest mate
- h#5
- deepest unique
- 229
- positions at that depth
- h#5
- deepest dual
- h#3
- deepest strict dual
- 78,819,823
- positions with a helpmate
- 7,945,202
- with a unique solution
- 121,110,528
- cells in the plane
- 38,135,370 bytes
- on disk
Deepest unique problems
h#5
8/8/8/8/8/n7/1R6/K5kR b - - 0 1
- Kxh1 Rh2+ Kg1 Kb2 Kf1 Kc3 Ke1 Kd3 Kd1 Rh1#
pure model mirror switchback 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
8/8/8/8/8/8/7n/K2Rk1R1 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ke2 Rb1 Nf1 Rb2+ Kd1 Rxf1#
- Kf2 Rh1 Kg3 Rdg1+ Kh4 Rxh2#
pure model mirror single-piece single-piece:black
Note: the diagram has no legal last move, so it cannot arise in a game.
h#3
8/8/8/8/8/8/2Rk4/K2nR3 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kd3 Rc1 Nb2 Kxb2 Kd2 Rcd1#
- Kxc2 Ka2 Kc1 Kb3 Kb1 Rxd1#
pure model ideal mirror switchback single-piece single-piece:black nocheck
Note: the side to move is in check in the diagram.
h#3
8/8/8/8/8/n7/1R1k4/K4R2 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kc3 Ra2 Kb4 Rb1+ Ka5 Rxa3#
- Nc2+ Ka2 Ke2 Rf2+ Kd1 Rb1#
pure model mirror single-piece single-piece:black
Note: the side to move is in check in the diagram.