Think about Milos Forman’s multi-Oscar-winning 1975 adaptation of the Ken Kesey novel, and the first thing likely to come to mind is Jack Nicholson’s performance. It’s extraordinary, a completely uninhibited powerplay, which dominates the screen. But what’s remarkable, when you watch this BFI rerelease in honour of Nicholson’s 80th birthday, is the way Forman is able to balance this enormous, film-dominating turn, and draw our eyes to the supporting characters – to the scaly chill and stillness of Louise Fletcher’s glare as Nurse Ratched, to the immutable sadness of Will Sampson’s Chief. It’s not just Nicholson’s performance that makes this film a masterpiece; it’s the fact that Forman was able to prevent that performance from capsizing the whole enterprise.