White to play. This position is from Tal–Benko, Candidates 1959. Black has just advanced with … e5, attacking the white knight. What has he overlooked? Answers to me at The Spectator by Tuesday 19 May 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.