Black to play. Yakubboev-Kramnik, Airthings Masters 2023. White’s last move, Re7-e6, was a blunder, allowing Kramnik to land a decisive tactic. What did he play? Email answers to chess@spectator.co.uk by Monday 20 February. 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.