Black to play. This is from Karpov-Korchnoi, Dortmund 1994. In this unusual position Karpov has two queens but Korchnoi’s forces coordinate much more efficiently. His next move led to a decisive material gain. Can you see it? Answers via email to firstname.lastname@example.org by Tuesday 17 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 Bxf6
Last week’s winner Stuart Perry, London SW4