The title and the epigraph alone—Godard’s “cinema lies, sport doesn’t”—suggest an array of Gallic musings about athletics. When writer-director Julien Faraut tells us he put together this documentary from 16mm rushes shot for the French Sports Institute (INSEP) at the 1980-1984 French Opens, we fear we may get a dry technical critique of an idiosyncratic tennis genius.

But to borrow the subtitle from Willa Cather’s story “Paul’s Case,” John McEnroe: In the Realm of Perfection turns out to be an extraordinary “study in temperament.” It enables us to read the displays of outrage and disdain that earned John McEnroe the nickname “Superbrat” as expressions of candor and super-sensitivity, even when they function as psychological weapons or ploys to control momentum on the court. This movie is a complex portrait of the athlete as a young artist in what proved to be his dominant period. He was ranked number one for four years straight and in 1984 attained what remains the highest win rate (96.5 percent) since the start of the Open Era (1968), when professional tennis players began competing with amateurs in major tournaments.

John’s case pivots on a mismatch of sensibility and environment. The same Open Era that made McEnroe a star produced infuriating distractions for him both on the court and off. The movie reveals his acute discomfort at a photo session, so we can imagine how he felt in game mode with hordes of TV cameramen and news photographers breathing down his neck.

Even INSEP director Gil de Kermadec, who admired McEnroe immensely and covered him excessively, added to the wunderkind’s annoyance. His ARRI High Speed 16mm camera (shooting at 120 frames per second for slow motion) produced a whirring sound that reverberated over the red clay of the Roland Garris stadium. A shotgun microphone in an ominous black windscreen further unnerved McEnroe.

These alien presences accented the Open Era’s new media-friendly careerism—not McEnroe’s thing at all. “At heart a true amateur sportsman” is how McEnroe’s biographer Richard Evans describes him in John McEnroe: Taming the Talent (1990). “One can just see him wandering around [the Queen’s Club] with his socks around his ankles, clad in the same pair of wrinkled shorts that he had worn to whip some bemused opponent the week before, his school scarf trailing from his neck . . . McEnroe would have been much happier amidst the camaraderie of the amateur sporting world with its code of honour than the code of conduct he faces on today’s cut-throat professional circuit.” This film proves Evans right. In one revelatory stretch, we see McEnroe spot, then stare back at de Kermadec’s camera, as paranoia and distress cloud his eyes. These moments are telling and chilling, like the one in Rear Window when the killer, Raymond Burr, locks eyes with James Stewart through his camera lens.

The wiry champion, with his dense curly mop of hair, unselfconsciously dirties himself in the clay or whips off his shirt in the heat. He doesn’t have the slickness or the Body by Jake that became de rigueur for celebrities in the early ’80s. He doesn’t even like to practice, preferring to play doubles to stay in some kind of fighting trim. (His success in doubles, and in the Davis Cup, indicate that he was a great team player in what is largely a non-team sport.) When you actually hear his stream of complaints, what emerges from them, whether justified or far-fetched, is the disapproval any perfectionist would aim toward officials unable or unwilling to defend their calls. As Jean Renoir might have commented, “The awful thing about life is this: every jerk has his reasons.”

Although Faraut gets full credit for script and direction (Mathieu Amalric reads his words), the voiceover includes analysis from de Kermadec’s own movie about McEnroe’s style and feel for the sport. De Kermadec’s cameraman Nicolas Thibault provides descriptions of the shooting conditions. Serge Daney, the Cahiers du Cinéma critic-editor who wrote about the Sport of Kings for the left-wing newspaper Libération, ruminates about McEnroe’s mystique, the creative “friction” of playing tennis on red clay, and a tennis player’s filmmaker-like “invention” of his own time. (It’s unclear whether we’re hearing Daney’s voice or an actor’s.)

McEnroe’s fascinating charisma and bebop rhythms unify these disparate parts. When he’s standing still he stays in constant motion with arms, hands, and head. We’re eager to follow the bouncing ball even when he’s simply preparing to put it into play. What McEnroe called his “sideways serve” heightens his unpredictability, since his opponents can’t easily read where he aims to place the ball, and it propels him toward the net in his devastating serve-and-volley game.

The movie’s mid-section views him frequently in three-quarters profile, befitting his preferred slant at the baseline and respecting his mystery. The 16mm cinematography, with its boxy 1.33:1 aspect ratio, provides the ideal frame to view a single compelling human being. In the Realm of Perfection presents him as “a man who played on the edge of his senses. His entire body was capable of reacting to the slightest noise, the tiniest change of atmosphere.” He vibrates like a tuning fork or lunges like a dowsing rod, but some intricate and instinctive mental calculation propels each movement. Whenever a shot permits, we sense him taking a microsecond’s pause before he selects his return. He uses an infinite variety of slices and lifts to keep his competitors off-balance. He’s so responsive and expressive that we can tell whether he’s winning or losing—even if we don’t see the other half of the court.

We learn that Tom Hulce studied McEnroe before playing the title role in Milos Forman’s Amadeus. Faraut intercuts snippets from that film, including Mozart declaring, “I am a vulgar man, but I assure you my music is not.” Yet McEnroe couldn’t be more dissimilar from Hulce’s earthy jester. When McEnroe complains about calls, he doesn’t play the bawdy clown. He operates from genuine anger and dissatisfaction, sometimes with officials, other times with himself. McEnroe’s audiovisual power is formidable in and out of play, so Faraut’s rare inventions register as overkill. In the worst, he overdubs De Niro’s Jake La Motta in Raging Bull, asking his brother Joey, “You fuck my wife?” during one of McEnroe’s epic sulks.

The film culminates in a stirring time-stamped summary of McEnroe and Ivan Lendl’s 1984 French Open final, which features McEnroe at his most virtuosic and self-destructive. He performs with dazzling command. He goes two sets up while pinpointing his serves, sliding easily across the red clay. He destroys Lendl’s confidence with devastating volleys or masterpieces of misdirection that end with him chipping the ball over the net. Daney observed, “[Björn] Bjorg puts the ball where the other player is not; McEnroe puts the ball where the other player could never be.” Here that becomes an act of visual imagination as well as mental and physical dexterity.

Throughout the movie we hear conflicting theories about McEnroe’s eruptions and their consequences. Daney considers them a ruse meant to conjure hostility on all sides and make McEnroe feel as though he’s struggling with his back against the wall. (Daney thought the result was “sublime” tennis.) An unnamed commentator writes that McEnroe embodies the winning-is-everything ethos of football coach Vince Lombardi and “our harsh, violent times,” as if McEnroe has been targeting his flare-ups. But to my eyes they are, as David Foster Wallace once wrote, expressions of “the high-tension neurosis of a true genius.” Amazingly, his tirades more often empower than weaken him: their emotional release seems to lubricate his competitive drive.

In the Lendl match, however, as he says in his 2002 memoir You Cannot Be Serious (written with James Kaplan), “This headset at courtside started blaring, and it was hot, and suddenly what had been in the back of my mind flooded into the front of my mind, and the doubts started creeping in: I’ve been playing so amazingly, I thought. How can I keep it up? I know the squawking headset was an innocent technical glitch—it wasn’t as if anybody had said, ‘let’s screw McEnroe up,’ but that’s how I took it—and just like that, my concentration was shot.” In the film, we see him walk over to the headset and scream into the mike, then grow “fatigued and tight and feeling this whole thing slipping away.”

Since the film focuses explicitly on McEnroe’s quest to achieve perfection, it might seem odd to close on a match that he considers “sickening” to this day. But the loss to Lendl plays like a grand finale. It brings home that McEnroe’s rebellious behavior, no matter how poorly considered, was deeply felt. In the end, his controversial career comes off as a triumph of authenticity.

Michael Sragow is a contributing editor to Film Comment and writes its Deep Focus column. He is a member of the National Society of Film Critics and the Los Angeles Film Critics Association, and a contributor to the Criterion Collection.