Black to play. This position is a variation from Hou Yifan-Kramnik, Dortmund 2015. Black is a rook down. What does he have in mind? Answers to me at The Spectator or via email to victoria@spectator.co.uk or by fax on 020 7961 0058. The winner will be the first correct answer out of a hat, and each week I shall be offering a prize of £20.