High school may mark the beginning of adulthood, but in the fictitious town of Dillon, Texas, it's primarily the time one is forced to abandon childish things, whether it's the roar of adoring football fans or the notion that you'll live happily ever after with the hottie from your homeroom.

"Friday Night Lights," which returns Friday to network TV (the entire fourth season previously aired on DirecTV), has always been more interested in a teenager's first heartbreak than his first kiss. For every winning touchdown, there are seven fumbles. The alt-rock soundtrack is so moody and despondent, it could be used for a hip remake of "Love Story."

No one has lost more since last season than Coach Andy Taylor (Kyle Chandler). He may be a full-grown man, but he's been living the boyish fantasy of overseeing a championship squad for so long, he's ill prepared when the school board reassigns him to a cross-town school that can barely get through a 15-minute practice, let alone compete for a title.

In the season premiere, written by Jason Katims ("Parenthood") and directed by Peter Berg ("Hancock"), he makes a halftime decision that, at first, seems completely out of character, but makes sense once you absorb the fact that this is a man who has, for the first time in his career, been demoted to the bush league. He may not be as tough as he thinks.

It's just one of many adjustments for a series that has never flinched from reinventing itself, even as it continually reemphasizes its overall theme: Open hearts and clear minds aren't always enough to maneuver life's cruel twists.

Others battling the odds include Taylor's wife, Tami (the underrated Connie Britton), who remains principal at Dillon High, but must put up with the bullies who ousted her husband. Former QB Matt Saracen (Zack Gilford) must abandon his dream of studying in Chicago to care for his grandmother and makes extra dough by delivering pizza to the rich side of town. Newcomer Vince Howard (Michael B. Jordan) does his darndest to avoid gang life, until he realizes it's the only way he can afford to send his mother to a rehab facility.

And then there's former gridiron star Tim Riggins, played by Taylor Kitsch, the hunk for anyone who has graduated from the Jonas Brothers but is not quite ready to swoon over George Clooney. His journey -- from quitting college to coming within centimeters of his small-town dreams -- is at the heart of this season.

"Didn't you used to be Tim Riggins?" asks one girl, trying to give him a hard time.

"Still am," he mumbles as if he's trying to convince himself that he really is.

For many viewers, watching these characters get beat up week after week may be too rough a sport. We want Riggins to grow up. We want Saracen to find true love. We want Coach Taylor to get a bucket of Gatorade poured over his head. But the show's creators refuse to play to the crowd.

What they want -- and what we get -- is tragedy, albeit with cheerleaders, keggers and the occasional ride to Lovers' Point. As I've said before, "FNL" is not about football. It's about swallowing the tears, manning up and getting back in the huddle. Kudos to DirecTV and NBC for keeping the game going, even if it leaves loyal viewers a bit battered and bruised.

njustin@startribune.com • 612-673-7431