A problem by Edward John Moreton Drax Plunkett, 18th Baron of Dunsany
(1878 – 1957), better known as Lord Dunsany. Primarily a writer and
dramatist, chess was one of his many interests. Here, some retroanalysis
is needed to determine the possibilities in the position.
Black has made 6 pawn captures, which accounts for all of the missing white pieces. Black’s last move could not have been b1B, dxe5 or dxc6, because each would have needed extra captures (dxc6 would make the bishop a promoted pawn). If the last move was by the king or rook Black cannot castle and 1.Ke6 any 2.Rh8 solves. If the last move was Pe7-e5 Black can castle but 1.dxe6 e.p. any 2.Rh8 solves. So, a straightforward example of Partial Retrograde Analysis? No! The last move could not have been Pe7-e5 because that would mean that all of the pawn captures took place on white squares, but one of the captured pieces was the bishop from c1. 1.Ke6 is the unique solution. T.R.Dawson reported that many FCR solvers fell into Dunsany’s trap.