You get the sense that Brad Pitt always knew he’d be a star. The story is now so well rehearsed as to be canonical in Hollywood legend and lore: Instead of graduating with a journalism degree from the University of Missouri, young Pitt famously quit college and lit out for the Golden West, where his corn-fed good looks and athletic self-confidence would serve him well in an industry where style so often — and so profitably — trumps substance.

And he was right: After toiling in B movies (with the odd gig in a chicken suit here and there), Pitt vaulted to fame with almost unseemly ease in 1991 with “Thelma & Louise,” in which an otherwise tiny role — as the sexy ne’er-do-well who gives Thelma her first orgasm — fused seamlessly with Pitt’s own physical gifts and sense of assurance to create a bona fide sex symbol.

So we can stipulate that, thanks to a convergence of genetics, timing and an innate gift for creating his own luck, success came easily for Brad Pitt. What wasn’t so simple was navigating stardom that only became more all-consuming with the advent of 24-7 gossip culture. The very attributes that made him such a compelling screen object — the ineffable quality that transcends mere handsomeness and makes him compulsively watchable — are what made him a commodity off-screen, as marketable for his marriage to Jennifer Aniston and subsequent romance with Angelina Jolie as for getting tushies in seats for “Ocean’s Eleven.”

But, as Pitt’s new film “Moneyball” attests, something extraordinary has happened on what could have been one long, lazy victory lap collecting one multimillion-dollar salary after another. The kid blessed with a preternaturally camera-ready face — who arrived in Hollywood without formal training and once said he would never be a great actor — has become, if not great, at least far more serious and interesting than his early career suggested he would.

Pretty people can act, of course. (George Clooney, Tom Cruise, Nicole Kidman.) But, given his beginnings as a sex symbol and a young actor who spent his early career “jacking around,” as he admitted to me in May, where he’s ended up seems all the more astonishing.

As Billy Beane — the Oakland Athletics general manager who in 2002 reinvented the baseball team with a recruiting technique based on pure statistics rather than the subjective criteria favored by old-school scouts — Pitt seems to bring every one of his prodigious gifts to bear, even the ones that seem to contradict each other. He moves with the swagger and cockiness of the jock he once was. But, at 47, age has begun to set in. There are visible bags under those famous baby-blues; the blond locks (remember “Legends of the Fall”?) are now a mousier brown, greasy and unkempt.

To channel the aggressively competitive Beane — who fought his own scouts and field manager to convince them his theories would work — Pitt presents a Falstaffian figure of excess, effectively banishing the golden boy that can still make grown women and men swoon. (“He shines,” a colleague said after Pitt visited The Washington Post offices a few years ago.)

Pitt’s still in terrific shape, but in “Moneyball” he exudes a careless, almost slovenly lack of vanity, scarfing down Twinkies in two bites or chugging a beer in one gulp. A subplot involves Beane’s efforts to stay involved with his young daughter, even though she lives miles away in Malibu with Beane’s ex-wife and her prosperous husband. It’s a tribute to his nuanced physical performance that Brad Pitt can make audiences believe a woman would ever leave a guy who looks like Brad Pitt.

And yet, hidden behind the Twinkies and the temper tantrums and the shaggy bangs, Pitt’s native charisma never disappears entirely. When Beane meets Yale-educated computer whiz Peter Brand (Jonah Hill), Brand seems to look on him with a mixture of fear and awe. Throughout “Moneyball,” Brand’s reactions to Beane seem inextricably entwined with Hill’s admiration for Pitt’s star power, not in the sense of godlike physical qualities but of the sheer force of his personality. (A scene late in “Moneyball,” when Beane leads a complicated telephone negotiation for pitcher Ricardo Rincon, plays like a one-man Abbott and Costello routine — or maybe Hepburn and Tracy, as Hill gazes at the fast-talking object of his affection in rapt adoration.)

So when Brand follows Beane to Oakland, filmgoers giddily go along for the ride, vicariously enjoying the seduction as if we were watching the popcorn rom-com Pitt never made. Even when he’s submerging his persona in character-actor scruffiness, he can still sweep Hill — and us — off our feet.

Still, as Beane, who in the film fights against a hidebound tradition of recruiting players based on the beauty of their swing or cut of their jawline, Pitt casts his lot unambiguously with the less telegenic but more reliable utility players who, despite awkward throwing styles or advancing years, help their team win baseball games.

And that ethos is precisely the one Pitt has embraced over the past six years. The 2005 action comedy “Mr. & Mrs. Smith” was the biggest smash of his career. But instead of following the money, he’s leveraged his star power to take consistently weird and wonderful chances, sometimes as part of a larger ensemble, sometimes carrying a picture on his own. He made quietly devastating use of a relatively small part in the multi-character “Babel” and was just as potent as a goofy, airhead gym rat in the Coen brothers’ comedy “Burn After Reading.” He gracefully ceded center stage to Casey Affleck in “The Assassination of Jesse James by the Coward Robert Ford” (itself a dreamy, sprawling meditation on the morphology of fame), then anchored David Fincher’s “The Curious Case of Benjamin Button” and, this year, Terrence Malick’s “The Tree of Life.”

Both those ambitious, uneven dramas found Pitt capable of the expressiveness, specificity and focus that distinguishes a performance from a mere star turn. But in the far more accessible, warm and viscerally satisfying “Moneyball,” Pitt seems finally to have achieved an equilibrium between the two — balancing the celebrity of the audience’s projections and the artist who went along for the ride on that fateful trip out of Missouri. He could have been a star, but it turns out that Brad Pitt was an actor all along.