h#8.5
k7/8/8/7p/8/8/5b2/3K3N w - - 0 1
- Ke2 Kb7 Kf3 Kc6 Kf4 Kd5 Kg5 Ke4 Ng3+ Kf3 Nxh5 Kg2 Kg4 Kh1 Kh3 Bg1 Ng3#
KNvkbp
5 pieces.
- h#10.5
- longest mate
- h#8.5
- deepest unique
- 12
- positions at that depth
- h#8.5
- deepest dual
- h#7.5
- deepest strict dual
- 542,136,729
- positions with a helpmate
- 2,273,390
- with a unique solution
- 355,074,048
- cells in the plane
- 227,848,570 bytes
- on disk
Deepest unique problems
h#8.5
7k/8/8/p7/8/8/2b5/NK6 w - - 0 1
- Kb2 Kg7 Kc3 Kf6 Kc4 Ke5 Kb5 Kd4 Nb3+ Kc3 Nxa5 Kb2 Kb4 Ka1 Ka3 Bb1 Nb3#
pure model ideal switchback self-block
Note: the side to move is in check in the diagram.
h#8.5
K7/2p5/2b5/N7/8/8/8/7k w - - 0 1
- Kb8 Kg1 Nb3 Bh1 Nd4 c5 Kc7 c4 Kd6 c3 Ke5 c2 Kf4 c1=R Kg3 Rf1 Ne2#
pure model ideal promotion underpromotion excelsior excelsior:black self-block nocapture nocheck umnov
Note: the side to move is in check in the diagram.
Deepest dual problems
Deepest dual with different first and last moves: h#7.5. The deepest dual overall is h#8.5, where the two solutions share a first or a last move.
h#7.5
8/K1p5/8/1b6/5N2/8/8/7k w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Nh3 c5 Kb6 c4 Kxb5 c3 Kc4 c2 Kd3 c1=B Ke2 Bf4 Kf1 Bh2 Nf2#
- Nh5 c5 Kb6 c4 Kxb5 c3 Kc4 c2 Kd3 c1=R Ke2 Rc2+ Kf1 Rh2 Ng3#
pure model ideal promotion underpromotion excelsior excelsior:black switchback self-block single-piece single-piece:black phoenix umnov
h#7.5
1K6/2p5/2b5/8/8/8/8/2N3k1 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Nb3 Bh1 Nd4 c5 Kc7 c4 Kd6 c3 Ke5 c2 Kf4 c1=R Kg3 Rf1 Ne2#
- Nd3 Bh1 Nf2 c5 Kc7 c4 Kd6 c3 Ke5 c2 Kf4 c1=R Kg3 Rf1 Nh3#
pure model ideal promotion underpromotion excelsior excelsior:black self-block nocapture nocheck umnov
h#7.5
8/K1p5/7N/8/8/8/8/3b3k w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ng4 c5 Kb6 c4 Kc5 c3 Kd4 c2 Ke3 c1=B+ Kf2 Bf4 Kf1 Bh2 Nf2#
- Nf5 c5 Kb6 c4 Kc5 c3 Kd4 c2 Ke3 c1=R Kf2 Rc2+ Kf1 Rh2 Ng3#
pure model promotion underpromotion excelsior excelsior:black switchback self-block single-piece single-piece:black nocapture umnov