Benny Safdie’s first solo feature, The Smashing Machine, may appear as disarmingly simple as the sports movie formula. But he has high-minded aspirations with his portrait of early UFC pioneer Mark Kerr. Likely none but Dwayne Johnson, who first entered the public consciousness through the WWF as “The Rock,” could match both the physical and performance needs to bring such a story to life. His limitations as an actor, however, hold the film back from landing the emotional punch it wants to deliver.

The Smashing Machine follows four pivotal years at the peak of his career and the nascent stage of the sport. Kerr navigates an assortment of issues, pulling his attention from the octagon. The demanding toll of UFC fighting on his body drives Kerr toward opioids, to which he develops an addiction requiring treatment and recovery. This energy spent battling his own demons only compounds the stress of his training at a time when the sport teeters on a precipice between poverty and prosperity.

The camera maintains a distance from the fights themselves as cinematographer Maceo Bishop only shoots from outside the matches, but there’s no clinical remove from the proceedings. Benny Safdie has long taken ownership of sound design in projects with his brother, Josh, and maintains that control in The Smashing Machine. The matches might look clean, but their audio mix captures the maelstrom of emotion and commotion. Dialogue stacks on top of diegetic noise and frequently some music on the soundtrack, creating a competition playing out for the ears as well as the eyes.

These layered textures also apply to scenes outside the arena – and are arguably more effective there. There’s far more immediacy in the brawls that take place in Kerr’s personal life with his partner Dawn Staples-Kerr, played by Emily Blunt. She’s looking out for their collective well-being and often faces the brunt of his rage for her attempts to exert some influence over the direction of his career.

These domestic scuffles play out for so much longer and with greater frequency than any UFC match in The Smashing Machine. Dawn’s refusal to take the metaphorical punches gives the film its fighting spirit. It’s these scrappy scuffles, not the professional bouts, that make the film’s real heart. Blunt in particular shines, taking what on paper might be little more than the SNL “every girlfriend from every movie about boxing ever” bit and imbuing the archetype with real soulfulness. She embodies Dawn’s feral frustration over a lack of recognition for her contributions to his success, which are intangible but no less real.

Dawn might punch above her weight, but she’s a decidedly supporting presence in The Smashing Machine. Safdie relies on Johnson to carry its weight on his (bulging and jacked) shoulders, and the strain shows. Kerr has to be the connective tissue between the emotional core of the relationship drama and the physical components of the UFC action. Far too frequently, the film feels locked into one mode and unable to access the other.

Safdie, whose technical prowess also includes presiding over the edit, often manages to work around his lumbering subject. Some clever splicing of key sequences helps clarify the thematic connections across the scope of The Smashing Machine. Yet there’s a missing element that only Johnson as the star can provide with his performance, and he never forcefully communicates the needs and desires of the protagonist.

The boxing movie, with Robert De Niro’s Oscar win for Raging Bull in 1980, first gave actors the incorrect impression that a bodily transformation could do the heavy lifting of a character. There’s a similar misconception with Johnson’s turn in The Smashing Machine, which relies on impressive prosthetic work from Kazu Hiro. This makeup guru turned Gary Oldman into Winston Churchill in Darkest Hour and Charlize Theron into Megyn Kelly for Bombshell to Oscar-winning effect, and there’s a similar “wow” factor to the many faces Johnson dons across the years.

But rather than enabling Johnson to demonstrate the effects of these weathered visages on his soul, the prosthetic work stifles his performance. His face is unemotive beyond the point of stoicism as a mere character choice. Any subtle displays belying Kerr’s tough façade get trapped behind the makeup. It has the effect of making any human connection to the hero of The Smashing Machine feel as sterilely calibrated as the ringside cameras.

Athletes are more than just their professional accomplishments. (Turn on ESPN at any given hour to see just how much narrative these programs foist upon players instead of treating them like lines in a box score!) In boxing and professional fighting, the framework is simple: A fighter enters the ring to take on both their stated opponent but also face down themselves. Within the boundaries of this primal, violent brawl, a film can explore ideas ranging from the allegorical to the visceral.

Beyond the presence of Dawn and another trainer-turned-rival in the ring, Mark Coleman (real MMA fighter Ryan Bader), there’s not much to The Smashing Machine on this mythic level in which people consume sports content. A slapped-on coda attempts to reframe Kerr as an unheralded pioneer for a sport now experiencing such explosive growth that Trump might host a fight on the White House lawn for America’s 250^th anniversary in 2026.

But this angle feels only lightly supported by the two hours preceding it. Johnson, with a big assist from Safdie, sure knows how to play the spectacle. The storytelling to make those moments resonate on a grander scale feels conspicuously absent.

Marshall Shaffer is a New York-based freelance film journalist. In addition to Decider, his work has also appeared on Slashfilm, Slant, The Playlist and many other outlets. Some day soon, everyone will realize how right he is about Spring Breakers.