I, Tonya **

Margot Robbie hits her marks as maligned Olympic figure skater Tonya Harding, but this bruising docu-comedy careens erratically between broad satire and unearned pathos while never quite finding its footing outside the rink. 

Is it worth 10? No 

Tonya Harding stands still, her steely gaze cutting through all the sneers and putdowns she's had to endure since grade school. Skates ready to glide through the ice, the only drama here is whether she can land that triple axel. Okay, so she feels her domineering mother's eyes on her, but here on the ice, she's not the poor Oregonian unsuccessfully attempting to earn her more moneyed peers' respect. She's a contender, performing to a cheesy rock song.

The skating sequences in “I, Tonya” adroitly place the viewers in Harding's headspace. This isn't a graceful athlete giving the judges the highbrow routines they want to see, but an in-your-face maverick bucking the classical-music trend. When she shines before the cameras, her joy and sense of fulfillment are infectious.

Alas, the bulk of “I, Tonya” unfolds outside that competitive skating rink, and the domestic dramedy we get in between those scenes leaves a lot to be desired. Director Craig Gillespie (“Lars and the Real Girl”) has assembled an impressive cast, headlined by Margot Robbie in the titular role, but the A-list names struggle mightlily to achieve verisimilitude. You feel everyone involved trying to “go indie,” but the finished product never stops feeling like the Hollywood version of tabloid fare. It wants the street cred but doesn't quite know how to get its hands dirty.

Which might have all been well and good, if Gillespie had been able to pull off that tonal high-wire act he set for himself. But the filmmaker, working from a screenplay by Steven Rogers, doesn't have the chops to handle the abrupt shifts from laughs to disturbing physical violence and back again. He gets off on the wrong foot from the get-go by opting for a faux-documentary framing device that has his characters' present-day incarnations speaking directly to the camera. (Think of a Christopher Guest mockumentary, only more self-consciously twee.)

The heavy-handed approach extends to our first glimpse of Tonya as a little girl, as her mother, LaVona Golden (Allison Janney, disappearing into the part), tries to enroll her in skating lessons. Robbie implausibly takes over the role while Harding is still in her teens, torn between LaVona's borderline-abusive tough-love guidance and more gentler coaching from Diane Rawlinson (Amy Nicholson, giving the film's sole understated performance). But the training sequences, at one point set to, of all songs, “Barracuda,” are dwarfed by the volcanic push and pull between mother and daughter. Critics have singled out Janney as playing LaVona as too much of a caricature, but let me take a moment to defend her. LaVona was a dark force of nature, a bitter viper who knew how to elicit her daughter's best athletic performance in the most deplorable way possible. There's no reason for Janney to hold back. Her LaVona is a hateful gargoyle, and justifiably so.

But “I, Tonya” also wants to be a romance of the dysfunctional kind, and this is where the movie really stumbles. Sebastian Stan from the “Captain America” films plays Jeff Gillooly, Harding's abusive husband, and the casting decision is akin to hiring a gardener to fix your plumbing. The film repeatedly reminds you Jeff's a dimwit with a nasty violent streak, but Stan can't play dumb, or scary, if his life depended on it. Gillspie puts viewers in the middle of the couple's brawls, and I didn't buy it for a second. It's a problem made all the more jarring by having Robbie break the fourth wall to address viewers directly at the most disruptive junctures.

Even more suspect is the way the movie handles the Nancy Kerrigan incident that turned Harding (unfairly, the filmmakers argue) into a pariah and media punching bag. Rogers' screenplay goes into the machinations behind the attack from several characters' point of view, yet reduces the victim in all this to a mere plot point. Gillespie pointedly refrains from showing her face. Harding's perceived threat to Olympic glory remains, for the most part, a blur just out of the camera's focus. The film makes no claim to be evenhanded, but a little effort to give Kerrigan the semblance of a personality, or at the very least more of a presence, would have gone a long way to make this portrait more complete.

It's up to Robbie to save the day, and she puts up an admirable fight. Even when the film stages her troubles at fever pitch, the “Wolf of Wall Street” star burrows deep to find the tormented soul behind all the headlines. But all of her efforts serve an erratic biopic that wants to indulge in tasteless mayhem without ever quite ringing true. A scene set at the diner where LaVona works draws sparks between Robbie and Janney. The lacerating exchange draws blood, and hints at the film “I, Tonya” could have been with more assured, and balanced, stewardship behind the camera.

But this misfire never quite shakes a white-trash dress-up vibe. That obtrusive artifice causes the film to pirouette in all kinds of wrong directions, sending it headfirst into a wall of poor creative decisions and whiplash-inducing missteps. I give this set a 5.