Helpmate tablebases Every solution to every position, precomputed.

← all materials

KRNvkn

5 pieces.

h#10
longest mate
h#8
deepest unique
2
positions at that depth
h#6
deepest dual
h#4.5
deepest strict dual
168,934,874
positions with a helpmate
12,331,361
with a unique solution
121,110,528
cells in the plane
98,373,781 bytes
on disk

Deepest unique problems

Only 2 distinct ideas exist at this depth.

h#8

5n2/8/8/8/8/3N4/3R4/1K1k4 b - - 0 1

  1. Kxd2 Ne5 Ke3 Kc2 Kf4 Kd3 Kg5 Ke4 Kh6 Kf5 Kh7 Kf6 Kh8 Kf7 Nh7 Ng6#

pure model ideal self-block nocheck

Note: the side to move is in check in the diagram; the solution begins with a capture.

h#8

5n2/8/8/8/kRN5/8/8/2K5 b - - 0 1

  1. Kxb4 Kd2 Kc5 Ke3 Kd5 Kf4 Ke6 Kg5 Kf7 Ne5+ Kg8 Kf6 Kh8 Kf7 Nh7 Ng6#

pure model ideal self-block

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#4.5. The deepest dual overall is h#6, where the two solutions share a first or a last move.

h#4.5

8/8/8/8/1n3k2/4R3/1N6/K7 w - - 0 1

Two solutions, with different first and last moves (2 starts, 2 ends).

  1. Ra3 Nd3 Ka2 Ke3 Kb3 Kd2 Nc4+ Kc1 Ra1#
  2. Rc3 Nd3 Ka2 Ke3 Kb3 Kd2 Rxd3+ Kc1 Rd1#

pure model ideal mirror

h#4.5

8/8/5k2/6R1/8/N7/8/K6n w - - 0 1

Two solutions, with different first and last moves (2 starts, 2 ends).

  1. Nc4 Ng3 Ne5 Nh5 Ng6 Kg7 Nf8+ Kh6 Rg6#
  2. Ra5 Nf2 Nb5 Kg5 Nd4+ Kh4 Rg5 Nh3 Nf3#

pure model switchback self-block nocapture umnov

h#4.5

8/8/8/8/6k1/n1R5/6N1/1K6 w - - 0 1

Two solutions, with different first and last moves (2 starts, 2 ends).

  1. Kc1 Nc2 Ne3+ Kf3 Nf5+ Ke2 Rf3 Ne1 Nd4#
  2. Kb2 Nc4+ Rxc4+ Kf3 Kc3 Ke2 Re4+ Kd1 Re1#

pure model ideal self-block umnov

Note: the side to move is in check in the diagram.