Black to play. This is from Spassky-Fischer, World Championship, Reykjavik (Game 5) 1972. This is probably the most famous ‘dark-square’ Nimzo-Indian game of all-time. How did Fischer finish off? Answers to me at The Spectator by Tuesday 23 June or via email to victoria@spectator.co.uk or by fax on 020 7681 3773. The winner will be the first correct answer out of a hat, and each week I am offering a prize of £20. Please include a postal address and allow six weeks for prize delivery.

Last week’s solution 1 … Rh1+

Last week’s winner Tim Leeney, Hartfield, East Sussex