Start a discussion to decide “the Greatest Living Actor”, and Brad Pitt's name probably won't come up. It's a crowded field: Robert De Niro and Al Pacino are still around, doing arguably their highest-profile work on television hawking Sky packages and bagels, while contemporary heavy-duty types Joaquin Phoenix and Jake Gyllenhaal (the leading men) and Michael Shannon and Ben Mendelsohn (the character actors) share the same ferocious magnetism and adaptability as those old New Hollywood masters in their respective heydays. And then, inevitably, talk must turn to Daniel Day-Lewis. (There should be an actors' equivalent of Godwin's Law just for DDL; as a “Greatest Actor” debate grows longer, the probability of Day-Lewis' name being thrown out nears 1.)

Brad Pitt's appeal as an actor should be obvious. He has the same ineffable movie star quality, that easy, screen-friendly charisma, of a Robert Redford or Paul Newman, though Pitt, like Butch and Sundance before him, is patently no chameleon. He's not Meryl; nobody's going to argue Brad Pitt could “play anything”. Pitt has given great performances, but where some actors are shapeshifters, Pitt's brand, like Redford's, has always been to reliably play variations of himself. Versatility, then, isn't the reason Brad Pitt has kept his name atop the marquee for the best part of three decades. This isn’t necessarily the best actor in the world, but put Brad Pitt’s career under a microscope and he may well look like the smartest.

Pitt’s easy screen presence might be Redfordian, but his intelligence as a Hollywood player recalls another old-school star. Burt Lancaster, a burly actor-producer whose wide-set eyes and toothful grin brought to mind a cheerful velociraptor, was not the greatest actor of his generation. Whether a heavy or a lover, a soldier or – in the case of his Oscar-winning turn in 1960’s Elmer Gantry – an opportunistic revivalist preacher, Burt more or less just played Burt. What kept him relevant were the films he chose to play Burt in. Lancaster's filmography, beginning with noir touchstone The Killers in 1946 and ending with GOAT sports movie Field of Dreams in 1989, is lousy with all-timers. As well as the aforementioned, Lancaster's resumé boasts such critically-adored classics as From Here to Eternity, Sweet Smell of Success, Run Silent, Run Deep, Judgment at Nuremberg, The Leopard, Seven Days in May, The Train, The Swimmer, Local Hero, and on and on and on.

There was nobody in Lancaster's time with as reliable an eye for a project as Burt. Like his, Brad Pitt’s back-catalogue is rich: Thelma & Louise, True Romance, Seven, Fight Club, Ocean’s Eleven and The Assassination of Jesse James by the Coward Robert Ford are all landmark films in their respective genres, but in just the last decade, Pitt has starred in another glut of great films (Inglourious Basterds, Moneyball, The Tree of Life, 12 Years A Slave, The Big Short, Once Upon a Time in Hollywood) and cult-classics-in-the-making (the day will soon come for both Killing Them Softly and The Counsellor). Rapturous early reviews suggest Ad Astra is another winner.

Brad Pitt has a hit-rate unequalled by anybody else in modern cinema. According to a 2016 article from Vox, this isn’t just speculative, but quantifiable. Comparing the average critical scores out of 100 of actors' movies on review aggregator Metacritic, Zachary Crockett named a top 15 of best-reviewed actors, including the likes of Michael Fassbender (69), Matt Damon (64) and George Clooney (62). Since then, on this scale, Pitt has surpassed all but Day-Lewis (73), now retired, and John C Reilly (Pitt's score is 64, Reilly’s is 65). Pitt's record, as producer, meanwhile, has been arguably even more impressive than as an actor.

Since The Departed, his first feature as producer, won the Oscar for Best Picture in 2007, Pitt has only become bolder, branching out from establishment types like Martin Scorsese with the foresight to bring soon-to-be-acclaimed filmmakers like Barry Jenkins, Andrew Dominik, Steve McQueen and Ava DuVernay into the Hollywood system on the basis of one or two scrappy indie projects. Pitt has an old-school movie producer brain – that’s knowing a good story, recognising talent and valuing both. The films Pitt produces regularly impact the cultural conversation. In the past five years alone, Pitt’s production company Plan B has helped to develop Selma, Moonlight, The Lost City of Z, Okja, If Beale Street Could Talk and the acclaimed upcoming drama The Last Black Man in San Francisco. (In that same half-decade, Pitt’s films as producer together amassed 11 wins and 25 nominations at the Academy Awards.)

That Pitt even continues to make such films – for the most part, dramas aimed at adults – while remaining not just relevant but vital (and richly rewarded), is a minor miracle. In a world where more than a third of box office takings now goes to Disney, the path of least resistance for an actor is to join an audience-friendly cinematic universe for the regular pay cheque and guaranteed career boost (even Robert Redford joined the Marvel gang in 2014, playing arch-villain Alexander Pierce in Captain America: The Winter Soldier). But, 2013’s World War Z excepted, Pitt doesn’t do blockbusters; and save for a knowing cameo in last year’s Deadpool 2, which saw his character introduced and killed in the same shot, Pitt has resisted the lure of superhero movies entirely. Pitt serves food-for-thought to grown-ups, and has maintained brand-name star status doing so.

Pitt started out in Hollywood in a uniquely privileged position; compared to some, he’s had it relatively easy. This is, after all, a good-looking, able-bodied white man who lucked out with an attention-grabbingly shirtless performance in what would prove to be a financially and critically successful film. But while Pitt has never really broken his popular streak since he emerged on the scene abs-first with Thelma & Louise in 1991, his contemporaries have experienced considerably more ebb and flow.

Consider the wavering fortunes of other megastars of 90s cinema. Consider Keanu Reeves, who's had a banner 2019 with a trifecta of meme-friendly roles in John Wick: Chapter 3, Always Be My Maybe and Toy Story 4, but whose woeful film choices post-Matrix (47 Ronin, anyone?) left him somewhat in the acting wilderness until a surprise renaissance began with John Wick in 2014. Consider Johnny Depp, whose growing laziness as an actor, coupled with his goodwill-squandering ‘personal troubles’, has left him akin to some sort of Hollywood ghost, ambling through movies no one sees and which can no longer justify his bloated salary. Consider Will Smith, whose ill-advised foray into 'serious' roles in the utterly beige likes of Seven Pounds and Concussion only saw the once-most bankable actor on the planet’s star plummet; Smith has since retreated back into juvenile blockbuster cinema in an attempt to recapture some of his former glory. Spies in Disguise will be released in cinemas this Christmas.

In 28 years Brad Pitt's star has never truly waned, even though, at the height of their powers, Keanu, Depp and Smith all similarly had their pick of films and filmmakers. But there’s having limitless opportunity and there is knowing what to do with it. After a period of abortive respectable drama in the mid-to-late-90s, Pitt re-energised with an instantly iconic role in David Fincher’s Gen X-defining Fight Club. After a recent spate of flops and curios put him in danger of losing his audience once more, Pitt course-corrected with a typically zeitgeist-y Quentin Tarantino movie.

Tom Cruise, who was considered by Tarantino for Pitt's role in Once Upon a Time in Hollywood, is the only other actor of the age whose run of success is comparable to Pitt's own – though some might say that leaving the more dangerous likes of Magnolia and Collateral behind to become a glorified stuntman in mediocre action movies (the Mission: Impossible series aside) is taking the easy way out. Pitt remains on the A-list with the kind of films that make year-end critics’ lists. He's amassed a $240 million fortune while cultivating a legacy career, making the kind of films that we'll be talking about long after Knight and Day or the Mummy reboot have been forgotten.

Pitt is underestimated for a reason. Intense media scrutiny of his private life, from Gwyneth to Jen to Angie (and the divorce), has often kept Pitt’s work a secondary concern in popular discourse. Then there's the very real concern that Pitt has just always been too pretty to be taken seriously. Tragically burdened with one of the most photogenic faces in human history, Pitt's surface has always provided more fascination for an image-obsessed press than, say, his knack for plucking auteurs from obscurity. (Even in advanced middle-age, Pitt taking his shirt off in one scene of Once Upon a Time has generated more column inches than the considerable merits of his actual performance in the film.)

What's more, successful stints playing airheaded or naif-ish, particularly early in his career, have seemingly also helped to create a lingering image of Pitt as some kind of doofus. It was an impression sealed, ironically, in spite of Pitt parodying this idea of himself, by playing an artfully stupid personal trainer in 2008's Burn After Reading. After all, how could someone who acts so convincingly dumb be so smart?

Ad Astra is released in UK cinemas on 18 September