At the beginning of this year Leonardo DiCaprio said that he was planning to take a ‘long, long break from acting’. He appears to be sticking with that plan. Following the The Great Gatsby, released in May, we’ll see him at the end of 2013 in The Wolf of Wall Street, his fifth collaboration with Martin Scorsese, and then his schedule is clear. But it would be a crying shame if he were to extend that break for too long, as it is arguably now, 20 years after the breakthrough moment that saw him acting opposite Robert De Niro in This Boy’s Life and Oscar-nominated in What’s Eating Gilbert Grape, that DiCaprio is coming into his own.

After becoming a global heartthrob with the double hit of Romeo + Juliet (1996) and Titanic (1997), DiCaprio seemed to be considering the ‘bankable megastar’ route to blandness (remember The Man in the Iron Mask?), but his hook-up with Martin Scorsese for 2002’s Gangs of New York signalled something different; an actor who was actually thinking about where his acting choices would lead him. While that film, and DiCaprio’s performance in it, don’t stand up to much scrutiny, the intervening decade has turned young Leo into the most interesting and unpredictable actor of his generation. He’s easily dismissed because of his youthful looks and apparently starry appearance, but when you pay attention to his acting decisions he is always the most interesting thing in a film. It’s DiCaprio’s furtive turn as Billy Costigan that gives The Departed (2006) its drama substance, while Jack Nicholson grandstands for the cheap seats.

DiCaprio is the youngest member of an elite club of leading men whose name alone can ‘open’ a movie (Brad Pitt, Will Smith and possibly still Tom Cruise round out that group). But he is the only one in that position willing to consistently play roles that attack all the established ideas of what a leading man should be. Would any of those other actors have chosen to play lead characters as troubled, complex and unreliable as DiCaprio did in Shutter Island and Inception, two of the biggest box office hits of 2010? Of course not. They have public images to uphold; their careers depend on it. But DiCaprio’s name above a film’s title guarantees only that the film will be worth watching, not that there will be anything like a ‘hero’ to be found there. In this light, his brilliant turn as hateful, racist slave-owner Calvin Candie in Quentin Tarantino’s Django Unchained just seems like showing off; an open provocation to his peers to demonstrate anything that comes close to his versatility. He has managed to completely separate his appeal as a film star from his public personality, giving himself an essential ‘unknowability’, despite his instantly recognisable face. One of the few other actors to have pulled off the same feat is Matt Damon, making their casting opposite each other in The Departed a stroke of genius.

All of which points to the conclusion that there is no other actor working today who is more suited to the role of Jay Gatsby than DiCaprio. Whether Baz Luhrmann’s vision does justice to Fitzgerald’s words is a separate issue, but his choice of leading man is spot on. Gatsby is an unknowable figure hiding troubled depths: you think you’ve got him pegged from his pristinely presented, privileged surface, but the more you investigate the more enigmatic he becomes until, like Fitzgerald’s narrator Nick Carraway, you realise you never knew him for a moment. He’s the ultimate fractured hero, who is anything but a hero, and that is Leonardo DiCaprio’s speciality.

The Great Gatsby is on general release from Thu 16 May.

The Great Gatsby trailer