This is a movie in which acting itself is a combat sport. Dwayne Johnson and Emily Blunt offer transformative performances, but it’s not always clear to what end in Benny Safdie’s real-life mixed martial arts fighting origin story The Smashing Machine (C+). Johnson plays MMA fighter Mark Kerr at the plateau of career success while simultaneously fighting painkiller addiction and a toxic marriage. It’s a film of very few surprises. Safdie’s watchful camera traces the pugilistic protagonist through globetrotting sports adventures and intimate domestic drama sequences, all the while artfully showcasing the man’s bombast and vulnerability. Emily Blunt is feral in her role as the spouse competing for his attention versus the sport itself. She chews whatever scenery her husband isn’t smashing; it’s a bit like another universe is calling and wants her performance back. Ryan Bader as Kerr’s longtime friend and fellow fighter actually comes across most interesting in the mix with empathetic Everyman appeal. It’s refreshing to see Johnson try a more overtly dramatic role on for size, and he acquits himself admirably on the journey, fully inhabiting a real guy seemingly very different from his own persona. Alas the film’s story doesn’t fully deliver on what clearly fascinated its makers, and no amount of artifice can conceal it’s just not all that interesting. In fact, at its most indulgent moments, the film feels a bit fabricated for awards season clip reels. See 2011’s Warrior for a more absorbing and nuanced take on the drama which can be harvested from the MMA.