h#7.5
8/8/8/8/8/7N/1q5P/k1K5 w - - 0 1
- Kd1 Qg7 Nf4 Kb2 h4 Kc3 h5 Kd4 h6 Ke3 hxg7 Kf2 g8=Q Kf1 Qg2#
promotion excelsior excelsior:white nocheck
Note: the side to move is in check in the diagram.
KNPvkq
5 pieces.
- h#8.5
- longest mate
- h#7.5
- deepest unique
- 17
- positions at that depth
- h#7.5
- deepest dual
- h#7
- deepest strict dual
- 479,316,843
- positions with a helpmate
- 8,748,078
- with a unique solution
- 355,074,048
- cells in the plane
- 295,346,096 bytes
- on disk
Deepest unique problems
h#7.5
8/8/8/8/8/5N2/q4P2/K6k w - - 0 1
- Kxa2 Kg2 Nd4 Kf1 f4 Ke1 f5 Kd2 f6 Kc3 f7 Kb4 f8=Q+ Ka4 Qa3#
promotion excelsior excelsior:white single-piece single-piece:black
Note: the side to move is in check in the diagram; the solution begins with a capture.
h#7.5
N7/8/8/8/q7/K1k5/P7/8 w - - 0 1
- Kxa4 Kd4 Kb4 Kd5 a4 Kc6 a5 Kb7 a6+ Kxa8 a7 Kb7 Kc5 Ka6 a8=Q#
pure model ideal mirror promotion excelsior excelsior:white 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#7. The deepest dual overall is h#7.5, where the two solutions share a first or a last move.
Only 2 distinct ideas exist at this depth.
h#7
8/8/7k/8/8/K7/P1q5/N7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Kg5 Kb4 Kf4 a4 Ke3 a5 Kd2 a6 Kc1 a7 Kb2 a8=Q Qb1 Qa3#
- Qb3+ Kxb3 Kg5 a4 Kf4 a5 Ke3 a6 Kd2 a7 Kc1 a8=Q Kb1 Qh1#
h#7
8/8/7k/3q4/8/K7/P7/N7 b - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Qh1 Kb3 Kg5 a4 Kf4 a5 Ke3 a6 Kd2 a7 Kc1 a8=Q Kb1 Qxh1#
- Qb3+ Kxb3 Kg5 a4 Kf4 a5 Ke3 a6 Kd2 a7 Kc1 a8=Q Kb1 Qh1#