"Win Win" is a high-school sports comedy about an unusual subject: grownups. Paul Giamatti, that most middle-aged of actors, plays Mike Flaherty, a New Jersey attorney and part-time wrestling coach whose shoulders are just about pinned.

Business is at a trickle, his forlorn office needs a new furnace, and the copy machine is bleeding ink. Mike's a decent guy, a family man, a churchgoing good neighbor who's affectionately called "Mr. Mayor." But we all know how many New Jersey mayors end up doing the perp walk. When Mike unethically assumes the salaried guardianship of a wealthy, senile client, he thinks he's created a win-win situation. In fact, he has put his livelihood and the trust of his family at risk.

Mike's struggles to regain his footing by hook or by crook are funny-uncomfortable, touching and above all relatable. The film is a win-win as a quirky indie comedy and an upbeat sports yarn.

Writer/director Tom McCarthy makes wrestling central to the story but uses his athletic metaphors creatively. Mike is introduced huffing along a jogging path, seemingly making respectable time, until two showoffs in slick running gear blast past. It's a snapshot of Mike's life: Try as he might, he's losing ground to go-getters. Even his high-school wrestling team is hopeless.

Then his elderly ward's runaway grandson Kyle appears on his doorstep, and Mike takes the boy in before he can ask too many awkward questions about his grandfather's care. Kyle looks like a surf punk but he's a tornado on the wrestling mat. His arrival upends both the team's prospects and Mike's guardianship hustle.

Films set in suburbia often feel synthetic and sit-commy, but McCarthy captures the texture of Jersey life like Margaret Mead with a sense of humor. This is a town where everyone knows everyone and a guy who wants a cigarette needs to hide behind the convenience store.

The characters are equally authentic. Mike's ethical lapse feels like a mistake triggered by desperation more than a scheme to bilk his ward. Giamatti's eyes, which can express a dozen shades of misgiving simultaneously, have never been so eloquent.

Amy Ryan is pitch-perfect as Mike's firecracker of a wife, Jackie. When Kyle first shows up in her home, she's so protective of her little daughters that she locks the boy in the basement. But she's also able to open up the withdrawn teen with the maternal affection he's never known. Bobby Cannavale is delightful as Mike's best friend Terry, a slick financial hotshot who signs on to assist the team as therapy for his post-divorce blues.

The revelation of the cast, though, is Alex Shaffer as Kyle. A longtime wrestler and first-time actor, he's dead-on as a kid with a core of anger that he can only express while grappling. His metamorphosis from an inscrutable newcomer to a cornerstone of the Flaherty household is another fine touch in a film where almost every choice is shrewd and true.

Colin Covert • 612-673-7186