White to play. Short-Timman, Staunton Memorial 2008. Short played 1 Qb3, missing an unusual opportunity to cause havoc with the pair of knights. Which move gives White a decisive advantage? Answers should be emailed to chess@spectator.co.uk by Monday 18 July. There is a prize of £20 for the first correct answer out of a hat. Please include a postal address and allow six weeks for prize delivery.

Last week’s solution 1 Bb6! wins the queen, since 1…Qxb6 2 Qxd7 is mate!

Last week’s winner Rodney Beddows, Bath