Legends such as Mike Tyson come along once in a blue moon, and frankly so do films that do them justice. James Toback’s brilliant documentary about a poor frightened boy from Brooklyn who becomes the youngest, and most feared, heavyweight champion in history owes everything to Tyson’s almost comical honesty. It’s one of those confessions you wouldn’t dream of hearing unless you were sitting in a church confessional rather than a plump sofa in a penthouse suite.

The 40-year-old bursts into tears when he remembers Cus D’Amato, the wily mentor and trainer who turned him from a teenage loser into a lethal weapon — but who died before he won the title. Tyson tells us he was fat and humiliated at school. Bullies put his glasses into milk cartons, and popped the heads off his pet pigeons. Boxing is a lifetime of payback.

The archive footage is a blistering medley of knockouts and feral aggression. Tyson in his pomp was a phenomenon; and too young to deal with it. The media attention ruined him. He squandered more than $200 million, and became a cartoon villain in his own lurid soap.

Tyson is wonderfully candid about his doomed love affairs, sex addiction and terrible business sense. “We were just kids,” he says about his marriage to Robin Givens. The promoter Don King was the most toxic man he met in his life. The rape charge that put the boxer behind bars for three years gutted Tyson of any last vestige of trust — in himself, as much as his blood-sucking entourage.

Toback’s split-screen moments, in which the film dissolves from gripping memories into something far closer to stream of consciousness, is pure documentary poetry. Hold tight for a guided tour of Tyson’s surreal descent into hell.

15, 88 mins

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