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 firstname.lastname@example.org by Monday 14 March. There is a prize of £20 for the first correct answer out of a hat.