The least interesting person in The Fighter is the fighter. That’s not to say that Mickey (Mark Wahlberg) is dull. It’s just that, outside of the ring, this Lowell, Mass., boxer is quiet, polite, eager to earn respect, and, most importantly, keep the peace in his family. Ah, the family: There’s his mother-cum-manager, Alice, a brash bottle-blonde in too-tight skirts who doesn’t understand why boxing isn’t everything to her son. There’s his brother, Dicky, a loose-limbed, bug-eyed current crackhead and former champion who knocked out Sugar Ray Leonard. And there’s his you-gotta-see-em gaggle of seven sisters, all teased hair and New England attitude, who won’t hesitate to stick up for their brothers or call a girl that Mickey’s into a skank.

Though the chorus of harpies are effective but interchangeable no-names, the mom, the bro, and the skank are likely Oscar contenders for their indelible, loudmouth portrayals courtesy of Melissa Leo (unrecognizable), Christian Bale (freakishly good), and Amy Adams (fun to see Miss Sweet Thing play a wide-voweled badass). Wahlberg is fine, too, but like a good ensemble player he nixes showboating in the service of the story, the better to play the eye of the chaos that swirls around him. Any scene-chewing would have tipped the feel of the film toward Actors Acting; as it stands, it’s just good (and often amusing) drama.

So a professional fighter, too often a loser and getting too old not to hold a menial job, battles the odds to continue doing what he loves? No, David O. Russell’s film isn’t exactly like Darren Aronofsky’s The Wrestler—at least, you’ll forget about any broad plot similarities by the end of the opening scene. In it, Mickey and Dicky are sitting for a filmed interview, ostensibly a documentary about Dicky’s comeback. Dicky’s been dubbed “the pride of Lowell” but does nothing but pump up his brother while Mickey smiles, almost bashful. Then the cameras follow them walking through the neighborhood, and they’re clearly kings. In fact, accompanied by the Heavy’s “How You Like Me Now?” they seem like the coolest people on earth.

But the documentary is really about crack addiction, and The Fighter’s story is just as much Dicky’s as Mickey’s. At the beginning of the film, Mickey is preparing for a fight that will bring in good money and a chance for him to move to a bigger apartment, which will better his odds of seeing his daughter more often. Dicky’s his trainer—when he shows up. But he’s usually too high to keep track of time, the result being the family banging on the front door of the crack house while he jumps out the back window. It’s funny and it’s tragic.

That fight doesn’t work out—Mickey’s intended opponent gets the flu, and he fights someone way over his weight class—leading him to consider giving up boxing altogether. Or, at least, his management: With Mom and Dicky so unreliable and bickering all the time, Mickey considers more professional offers with the caveat he leave the family behind. Encouraging him to do so is Charlene (Adams), a tough barmaid who pledges herself to Mickey just as soon as they start dating.

The Fighter is based on a true story (the real Mickey and Dicky are seen in the closing credits) and is less about perseverance than loyalty—to your family, to your friends, to your girl, especially when all those worlds collide. A trio of scripters sticks reams of curse-laden dialogue into the actors’ mouths, which they all spit out beautifully. Meanwhile, Russell’s camera is as fluid and the brothers’ boxing moves, whipping between characters during arguments and not shying away from the nastier parts of Mickey’s fights. The whole thing’s a knockout.