No. 729
Black to play. Schwetlick-Lecroq, 32nd Correspondence World Championship. White’s last move, Qd1-b3, is a blunder that can’t have been endorsed by a computer. What did Black play to force resignation? Answers should be emailed to chess@spectator.co.uk by Monday 21 November. There is a prize of £20 for the first correct answer out of a hat.
