In last week’s puzzle White can win by playing for a position with KQ v KQ in which he can force mate.

41.c4! Rxe3 (if Black doesn’t trade the rook ending is won) 42.Kxe3 Kxg3 43.c5 h4 44.c6 h3 45.c7 h2 46.c8Q h1Q 47.Qg8+ Kh3 48.Qh7+ Kg2 49.Qg6+ Kh3 50.Qh5+ Kg2 51.Qg4+ Kh2 52.Kf2 and mates.

This idea is worth remembering: it’s very easy to assume the position is drawn when both players promote.

The game actually continued 41. Rd3? Rb3 42. Re3 Ra3? 43. c4! and White, realising that opportunity had knocked a second time, soon won. Black’s only drawing options on move 42 were Rb8! and Rb1!. It’s worth your while looking at why 42… Rb8! is a draw but 42… Rb7? is a loss.