Chess - The Scotsman 24/12/12 - News - Scotsman.com HUGH Courtney sadly died earlier this year, aged 84, at his adopted home near Inverness, to where he retired in 1987 after a successful teaching career in England. Hugh Edward Guy Courtney was born 16 July, 1927, in Wells, Somerset and through the mid-1950s he enjoyed a Top 20 national UK ranking. But despite being a very strong player in his day, his chessic claim to fame came in writing CHESS Magazine's very popular annual Christmas Quiz that ran for over 40 years, the final one being published in 2004. "To astound, puzzle, bemuse, infuriate, delight, amaze and amuse" was what Hugh Courtney set out to do each year with his quirky seasonal offerings. It took him the best part of a couple of months to prepare his quizzes, where he would often throw in a Christmas Tree-themed puzzle, such as the one in today's diagram. This was the very first Christmas Tree chess problem (albeit an inverted one) ever created, and it came from the prodigious composer Thomas Rayner Dawson, who was regarded in his field as the "Oberon of Fairy Chess" - and it has a Scottish connection to it, by being first published in the Falkirk Herald in 1914. It's White to move and mate in two - but why is it, in this symmetrical position, is there only ONE valid key move, and not two equally valid keys as the symmetry would suggest? The answer is both easy and difficult. First of all, the knights can't deliver mate in two, so we have to start thinking retrograde here, and Black can only have played d7-d5 or f7-f5 as his last move, each allowing an en passant capture and mate next move. But a true puzzle has but only one solution, so which of the two is correct? Solution: The white pawns must have captured 10 times, which accounts for all the missing black pieces. That means Black's last move cannot have been d7-d5, because in that case the Bc8 was captured on its starting square, and a pawn could not have done that. Therefore, Black's last move could only have been f7-f5, and White mates with 1 gxf6 and 2 f7 mate!