LOS ANGELES — Jim Rome urges his listeners (or "clones," as he so lovingly calls them) to have solid takes, to bring it, when they dial into his sports talk radio show.

Patton Oswalt's character in "Big Fan," Paul Aufiero, ensures that his takes are solid because they are his raison d'etre. A portly Staten Island parking garage attendant stuck in his childhood home with his mother at age 35, Paul lives and dies for the New York Giants, and spends each day at work in his little metal box perfecting the arguments he'll make about his beloved football team when he calls into his favourite sports talk radio show each night.

Paul Aufiero feels completely believable in the hands of Robert Siegel, writer of the equally stripped-down and realistic "The Wrestler," who wrote the script and makes his directing debut here. Siegel has captured a very specific and recognizable kind of fan: the kind who refers to his team as "we," who derives confidence from walking around the neighbourhood in his puffy blue-and-red jacket and prepares all week for a few hours on Sunday.

You could describe him as pathetic in his arrested development, his lack of perspective. But Oswalt, best known for his comedy and his starring voice work in the animated "Ratatouille," brings enough depth to the character to make you feel sorry for him. This is especially true once Paul and his best friend Sal (Kevin Corrigan) have a run-in with the Giants' star linebacker, Quantrell Bishop (Jonathan Hamm), on a night in Manhattan that quickly shifts from veneration to violence.

Paul and Sal spy Quantrell and his pals driving around and follow them to an upscale strip club. This alone is ridiculous -- they're totally schlubby and out of place -- but then they have the chutzpah, or perhaps the cluelessness, to approach Quantrell in the VIP section. We'll just say their little meet-and-greet does not go as Paul might have hoped. Literally adding insult to injury, Quantrell is Paul's favourite player; he even as a poster of him hanging over his bed.

What follows is a conflict of loyalty versus justice in which Siegel offers no easy answers. Everyone around Paul urges him to tell the truth, including his brother (Gino Cafarelli), a flashy lawyer with a trashy wife (Serafina Fiore). But within Paul's twisted set of priorities, the fate of the Giants' season is more important than his own. So is his standing among his fellow callers, including his nemesis to the south, Eagles fan Philadelphia Phil (Michael Rapaport).

He truly believes all that, and "Big Fan" sells that concept without judging him. The vigilantism that drives Paul to the film's climax may seem a bit too derived from "Taxi Driver," but even that doesn't go as planned. What's left is a vivid portrait of an exceedingly ordinary man for whom there's no great epiphany or cliched redemption -- and that may be Siegel's trickiest play of all.

Three stars out of four.