[Retros] Fastest mate? :-)

[Elkies, Noam]

Andrew buchanan <andrew at anselan.com> writes:

> Thanks for this. Sorry I wasn't clear.
>
> Why do we need to prove that Black can't have just moved?
> (Apart from making the problem eligible for this mailing list :-) )
>
> The "fastest mate" stip doesn't seem to require that.
> Whoever has the move, the fractional mates are faster.
> It just happens that we can also show Black didn't move last,
> but the logic of the rest doesn’t build on that.

That's true -- once one accepts that the diagram might be
in medias res.  But this makes it a joke problem, and thus
potentially unfair to the unprepared solver.  Making the position
unreachable WTM warns the solver to expect sneaky content.
(And yes, it also might remind people on this mailing list of
a precedent that they might not have recalled otherwise.)

NDE