White to play. This is from Carlsen–Karjakin, New York play-off (Game 4) 2016. What was Carlsen’s stunning move to retain the world title? Answers to me at The Spectator by Tuesday 10 January or via email to victoria@spectator.co.uk. There is a prize of £20 for the first correct answer out of a hat. Please include a postal address and allow six weeks for prize delivery.
 
Last week’s solution 1 Nf5
Last week’s winner Iain Chadwick, Walton, Cheshire