h#5.5
8/7k/8/8/8/1q6/Q7/K2q4 w - - 0 1
- Qb1+ Qdd3 Qe1 Qf7 Kb2 Qdg6 Kc3 Kg7 Kd4 Kf6 Qe5#
pure model ideal self-block nocapture
Note: the side to move is in check in the diagram.
5 pieces.
8/7k/8/8/8/1q6/Q7/K2q4 w - - 0 1
pure model ideal self-block nocapture
Note: the side to move is in check in the diagram.
8/8/5k2/8/6Q1/q7/8/Kq6 w - - 0 1
Note: the side to move is in check in the diagram; the solution begins with a capture.
8/4Q3/6k1/8/8/3q4/q7/K7 w - - 0 1
pure model ideal self-block nocheck
Note: the side to move is in check in the diagram; the solution begins with a capture.
Deepest dual with different first and last moves: h#5. The deepest dual overall is h#5.5, where the two solutions share a first or a last move.
Only 2 distinct ideas exist at this depth.