The Retrograde Analysis Corner
An Ortho-Reconstruction is a maneuver changing the side to
move but leaving everything else unchanged. It is sometimes used in
forward problems (e.g. to put Bl. in zugzwang). In retros it may be
used e.g. to overcome a retro-opposition.
Here is an example:
La Genesi delle Posizioni,
11+13. Release the position
Here is an easy example:
32 Personaggi e 1 Autore,
12+12. Black to move. Ortho-Reconstruction
(I.e. reach the same position with White to move in the shortest number
Note that "leaving everything else unchanged" may involve
castling rights, etc.
[Q] What is the length record with legal position?