[Retros] "half" proof games

[Noam Elkies]

Richard Stanley asks:


> is there *any* sequence of n White initial moves so that

> Black has a unique way to mate White on Black's nth move?

> (All n Black moves should be unique.)


1 f3 ... 2 Kf2 ... 3 Ke3 ...#  seems to have a unique solution.
The thing that makes the 1 f3 ... 4 Kh4 ...# puzzle memorable
is Black's third move, which is counterintuitive to practical
chess players (who would play the Queen *there*?) and possibly
also to problem solvers (since one would expect to use the built-in
d8-h4 line).

NDE