h#6
K7/8/8/8/5R1p/7k/6R1/8 b - - 0 1
- Kxg2 Kb7 h3 Kc6 h2 Kd5 h1=R Ke4 Kh2 Kf3 Rg1 Rh4#
pure model ideal promotion underpromotion self-block nocheck
Note: the solution begins with a capture.
KRRvkp
5 pieces.
- h#7
- longest mate
- h#6
- deepest unique
- 43
- positions at that depth
- h#6
- deepest dual
- h#3.5
- deepest strict dual
- 245,130,713
- positions with a helpmate
- 28,408,447
- with a unique solution
- 355,074,048
- cells in the plane
- 103,892,284 bytes
- on disk
Deepest unique problems
h#6
8/7R/6Rk/8/8/1p6/8/K7 b - - 0 1
- Kxh7 Kb2 Kh8 Kc3 b2 Kd4 b1=R Ke5 Rb8 Kf6 Rg8 Rh6#
pure model ideal promotion underpromotion self-block nocheck umnov
Note: the diagram has no legal last move, so it cannot arise in a game.
h#6
7R/7k/8/6R1/p7/8/8/K7 b - - 0 1
- Kxh8 Kb2 a3+ Kc3 a2 Kd4 a1=R Ke5 Ra8 Kf6 Rg8 Rh5#
pure model ideal promotion underpromotion self-block kniest
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#3.5. The deepest dual overall is h#6, where the two solutions share a first or a last move.
Only one position exists at this depth.
h#3.5
4R1R1/5k2/8/8/8/8/1p6/K7 w - - 0 1
Two solutions, with different first and last moves (2 starts, 2 ends).
- Ka2 b1=R Ra8 Rb8 Rg7+ Ke8 Rxb8#
- Kxb2 Kf6 Kc3 Kf5 Kd4 Kf4 Ref8#
pure model ideal mirror promotion underpromotion single-piece single-piece:black
Note: the side to move is in check in the diagram.