He effectively downplayed his corruption – “taking a dive for the short-end money”, to quote the On the Waterfront speech which De Niro’s LaMotta is shown blankly running through for his nightclub turn – and the impact of his arrest.

Intentionally or not, Scorsese took LaMotta at his own cordial and lenient estimation of himself. Scorsese took the real LaMotta and merged him with Midge Kelly, the boxer Kirk Douglas played in Mark Robson’s Champion (1949) and Zampanò, the raging, self-hating clown played by Anthony Quinn in Fellini’s La Strada (1951). Inevitably, the film wound up inflating his boxing abilities and his importance in the sport’s history. Scorsese and De Niro both saw how this flawed minor character was movie gold, and together they made of him a mythical or tragic figure in his own lifetime, alchemising his sleaziness into something compelling, exalting him with the luminous beauty of black-and-white photography, eerily dreamlike fight sequences and the musical sob of Mascagni’s Cavalleria Rusticana on the soundtrack. He was of course unforgettably played by De Niro but I thought in later years he more resembled that other Scorsese player Paul Sorvino, or maybe Tony Sirico, who played Paulie Walnuts in The Sopranos. In his later years, his broad, battered face looked like a shovel with a cheeky grin. After his boxing career, he became a C-lister celeb, with walk-ons on TV and the movies, and was actually arrested and briefly imprisoned for introducing men to underage girls at his club in Miami. There were continuous rumours, which LaMotta could hardly deny, that he took money to throw fights. He was always notorious for a brawling, bullying style in the ring, combined with a fanatical, granite-skulled ability to absorb punishment – very different from the willed rope-a-dope strategy of Ali.

LaMotta’s shady reputation clouded his achievement.

Raging bull in colour