Athletic accomplishment at the very highest level is the subject of Gabe Polsky’s documentary. To illustrate what he means, his film features extended interviews with acknowledged superstars in three sports: hockey great Wayne Gretzky, football star Jerry Rice and soccer legend Pelé, and adds archival footage of basketball’s Michael Jordan and boxing’s Muhammad Ali, among others, for good measure.

But Polsky is interested not only in description, but in analysis and explanation. To that end he includes equally extensive interviews with David Epstein, journalist and author of “The Sports Gene,” and British educational theorist Ken Robinson, as well as excerpts from archival observations from some of those who have coached superstars.

The general conclusion arrived at is that excellence in performance on the field, the court or the ice is a matter of both nature and nurture. Innate talent is necessary, but it has to be cultivated in a fashion that allows the unique characteristics of each individual to flourish. While the cookie-cutter approach of much of the training regimen of today’s kids, emphasizing statistical norms, rote styles and early specialization, might achieve adequacy,it does not encourage brilliance.

The interviews emphasize this point. The greats note that they did not concentrate on the sport they eventually excelled in as kids, but played a variety of them, sometimes positively preferring others. Parents like Gretzky’s father talk about giving their children freedom and the chance to have fun, rather than trying to fit them into some mythic winning pigeonhole and force them to practice endlessly. And the effective coaches place importance on recognizing the particular attributes of players rather than compelling them to accommodate themselves to a single mold. Each of the three stars emphasize how important it was to find coaches who urged them to “do their thing”—Gretzky to score (though his defensive play was unspectacular), Rice to run (though off the field he was no speedster) and Pelé to take unconventional moves (when other players would play it safe).

Epstein and Robinson chime in along similar lines; they are particularly strong on using words like “artistry” and “creativity” to describe the play of great athletes, especially in team sports—their ability to keep track of everything around them and to be a step ahead of everyone else in terms of what’s happening, are to them comparable to the playing of a great pianist, or the performance of a superb actor, or the foresight of a painter or sculptor. Numerous “greats” from other fields—like the Beatles and David Bowie—are cited as examples of similarity to athletes who eschew conformity to find their own mode of expression.

So the message of “In Search of Greatness” comes down to an insistence that sports training has to recognize talent but encourage its development in ways particular to each child; compelling conformity and demanding constant practice will leech the enjoyment from sports and lead at best to competence, not greatness.

In terms of filmmaking, Polsky presents the argument in a fashion some viewers may find frantic, even exhausting, marked by quick cuts and speedy montages of archival material, found footage and newly-shot data, courtesy of editor Marco Capalbo, and push forward-pull-back motion in the interview excerpts, a choice presumably of cinematographer Svetlana Cuetko. One might sometimes wish for a cooler, calmer hand at the wheel.

But parents might rethink pushing their kids into conventional, often brutally demanding, highly regimented sports training programs after seeing the film. Though uneven and at times overstuffed with imagery and generalization, it offers a useful message for obsessive “sports dads” to hear.