It’s not really a sports movie without one, is it — the locker-room speech with the big metaphor, complete with close-ups, pregnant pauses and rousing yells? But what of the project that ultimately takes on its metaphor for the way it works as a movie?

“Be perfect” is the rallying cry in Friday Night Lights. And while it’s not perfect in the traditional sense, it is in the way the movie defines it — being confident you’ve done the best you can, no matter what the scoreboard says. 

It’s how co-writer and director Peter Berg can feel about his highly anticipated adaptation of his cousin H.G. Bissinger’s acclaimed book of the same name about high-school football’s reign over Odessa, a small Texas town.

As Billy Bob Thornton’s Coach Gary Gaines puts it early on, football is not about one player or even two players. It’s about a team. Berg’s movie is, for all narrative purposes, only about three players, a coach and a parent. When we get the usual close-ups of those characters, we know exactly what their dreams and demons are.

The rest? Well, when they flash the obligatory where-are-they-now subtitles at the end of the film, it’s a struggle to remember just exactly what position a couple of them even played. (One of them represents yet another wasted opportunity for actor Jay Hernandez, who has squandered his stellar debut in crazy/beautiful with next-to-nothing roles.)

Then again, no film with a reasonable run time could tell every player’s story. Berg’s only fault is trying to force a connection to certain faces when there’s none there.

And those minor bugaboos don’t change the fact Friday Night Lights is a tremendously entertaining, character-driven sports movie. Berg’s pacing is perfect, measuring out gridiron adrenaline fixes and emotional reflections equally.

Plus, it’s visually brilliant. Tobias Schliessler’s claustrophobic, documentary-style cinematography burrows into the huddle and in the heart. 

And really, what is the film if not a documentary with actors? It begins with the start of the 1988 season’s training camp for the Permian High School Panthers, a team that has come to define destiny and expectations for its key players.

In his second season, Coach Gaines needs to prove his hire was a good one to all the Odessa bigwigs who put Mafia-like squeezes on him to promise wins. As the possibility of football beyond high school looms, quarterback Mike Winchell (Lucas Black) must choose whether to improve his own life by leaving town or his ailing mother by staying.

Running back Boobie Miles (Derek Luke) has the invincible ego of a pro player but, as he finds out quickly, the vulnerable body of a mere mortal. And butterfingers receiver Don Billingsley (Garrett Hedlund) lives in the drunken shadow of his football-hero father (Tim McGraw), whose disappointment expresses itself in violent ways.

The film boasts numerous impressive performances — Luke’s early flashiness degenerates into genuine concern for his future, and Black has the face of Dermot Mulroney and the squinty focus of Charlie Sheen.

But the best work here comes from the character around whom all the others orbit. Making it look effortless, Thornton’s work is largely reactionary, as much a guidance counselor and parent as a coach. When he does get riled, his fury bears the same bite as R. Lee Ermey’s drill sergeant in Full Metal Jacket. The “be perfect” speech, bound to burn its way into the brains of high-school athletes everywhere, puts it over the top.

Aside from its big speeches, Friday Night Lights works because each play and conversation is filled with the equally nervy feeling of how fate could turn on its characters at any moment. It’s exciting and heartbreaking, sometimes both at the same time.