Black to play. Shirov-Kramnik, Groningen 1993. Shirov threatens Rg3-h3+ so Kramnik forced a draw: 1…Rxg7+ 2 Rxg7+ Kh6 3 Rg8 Kh7 etc. Which move would have won Kramnik the game? Email answers to chess@spectator.co.ukby Monday 14 March. There is a prize of £20 for the first correct answer out of a hat. Please include a postal address.

Last week’s solution 1 Qg8+! Qxg8 2 Rh1# or 1…Kxg8 2 Rxa8+ wins. Other tries lead to stalemate or perpetual check e.g. 1 Qd4 Qd8+ 2 Qxd8 stalemate or 1 Qd1 Qg2+ etc.

Last week’s winner Kevin Lott, Warnham, Horsham, West Sussex