KQBvkq

h#5.5

7B/7k/8/6Q1/8/8/1q6/K7 w - - 0 1

1. Kxb2 Kxh8 Kc3 Kh7 Kd4 Kh8 Ke5 Kh7 Kf6 Kh8 Qg7#

pure model ideal switchback single-piece single-piece:black kniest pendulum nocheck

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

h#5.5

6Bk/4Q3/8/8/8/8/1q6/1K6 w - - 0 1

1. Kxb2 Kxg8 Kc3 Kh8 Kd4 Kg8 Ke5 Kh8 Kf6 Kg8 Qg7#

switchback single-piece single-piece:black kniest pendulum nocheck

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

h#5.5

7k/7B/8/6Q1/8/8/1q6/K7 w - - 0 1

1. Kxb2 Kxh7 Kc3 Kh8 Kd4 Kh7 Ke5 Kh8 Kf6 Kh7 Qg7#

switchback single-piece single-piece:black kniest pendulum nocheck

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

h#4

5k2/6B1/4Q3/8/8/6q1/2K5/8 b - - 0 1

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

1. Kxg7 Kd2 Qg6 Ke3 Kh6 Kf4 Kh5 Qh3#
2. Qxg7 Kd3 Qh8 Ke4 Kg7 Kf5 Kh7 Qg6#

pure model ideal self-block nocheck

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