White to play. This position is from Alekhine-Flohr, Bled 1931. White has a positional advantage but can you spot the crushing tactical blow? Answers to me at The Spectator by Tuesday 9 February or via email to victoria@spectator.co.uk or by fax on 020 7681 3773. 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 Rxf7

Last week’s winner Robert Lee, Hampton, Middlesex