New documentary looks at what made the 1980s tennis champion so great, and also why he was so volatile on the court.

Tennis legend and commentator John McEnroe has become the subject of several films recently. At last year’s Toronto International Film Festival, director Janus Metz Pedersen and screenwriter Ronnie Sandahl captured the essence of McEnroe’s rivalry with the centered, machine-like Björn Borg in their dramatic portrayal of Borg vs McEnroe. Now, the documentary John McEnroe: In the Realm of Perfection, directed by Julien Faraut, provides a thoughtful and critical analysis of what fueled the greatness of the volatile tennis champion of the 1980s.

We tend to love team sport narratives (Remember the Titans, We Are Marshall) that show the unification of disparate individuals in pursuit of a common goal. Or, when we turn our attention to a single player, we long to spotlight the trailblazers (think Jackie Robinson in 42), who battle social and cultural odds in addition to performing spectacular physical feats.

There is something monumentally self-centered when we turn our attention to a virtually lone figure on the field of play. Their efforts to achieve success and glory sometimes take a backseat to their personalities. In order to merit such detailed investigation, they flaunt a certain level of grandiosity. We imagine these players to be egomaniacs and divas who chose their sports because they knew they would never have to share the spotlight with a team. There is no “celebrity story” — which fuels our interest in athletes and artists, especially in this social media-defined age — if the subject turns quietly inward and never allows the fans to glimpse behind the curtain. We desire and thrive on their naked and unfettered expression; we like to see them cut loose from propriety.

If we were to seek out a poster child for this angle, we might not find a better model than McEnroe, the classically brash former champion known as much for his epic clashes with linesmen and chair umpires as his battles with his top competitors on the pro circuit, like Borg and Ivan Lendl. In interviews, he adopted alternating poses — a sullen unwillingness to address the camera (sometimes going so far as to hold up a hand or push the offending lens away) and an almost feral stare-down with the camera and the interviewer. In today’s world, that approach would complement an aggressive social media profile.

In some ways, an argument could be made that McEnroe was born at the wrong time; he would have been the perfect exemplar of the sports diva on the current stage, even more so than he was in the 1980s. But in truth, that assessment misses the mark completely.

What In the Realm of Perfection reveals is that there was a method behind the volatility and the madness of McEnroe’s persona. The film, with its spot-on narration from actor Mathieu Amalric (who eerily becomes the ideal voice for McEnroe as the film progresses), starts off with a look at old footage of tennis players. That’s intended to clinically illustrate how form and function integrate in tennis. What we get is an instruction manual for building the perfect tennis player from the groundstrokes up.

Enter McEnroe, who upsets the logical progression and order of things. The footage of his game and the accompanying analysis uncover how his instincts and nuanced readings of his opponents expose the flaws in regimentation. Perfection, it turns out, requires an ability to adapt right in the moment, which McEnroe does like few others.

Yet he still adheres to a desire to control his environment and the game, which explains his volcanic outbursts. Faraut helps us to appreciate that the behavior we saw and misrecognized as bullying and egomania was, in fact, McEnroe’s attempt to counter what he felt were efforts to hinder his pursuit of perfection.

Borg vs McEnroe, which featured Shia LaBeouf as McEnroe, embraced the assumed narrative of the tennis great as an emotional powder keg waiting to explode. It set him opposite the self-contained Borg (Sverrir Gudnason) and gave audiences a simplistic contest. Thankfully, In the Realm of Perfection provides greater insight into the mind and motivation of an athlete engaged in a larger struggle. (Opens Friday, Aug. 31) Grade: A