15-02-2013, 06:05 PM
I haven't tried to get the position from the start, but I think the pawn has to be on f5 on the basis that if it were possible for the pawn to be on f4 then it's also possible for the pawn to be on f5 and therefore the only unique solution is for the pawn to be on f5. (I'm hoping this makes at least some sense but I've not done many of these before so it might be nonsense?)