No. 725
White to play. Mamedyarov-J. Polgar, Fide World Blitz, Dubai 2014. Black is lagging in development, and her last move, 10…Nb8-d7, gifted White a tactical opportunity. Which move won the game for White? Answers should be emailed to chess@spectator.co.uk by Monday 24 October. 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 Be2!