Johnson’s new movie, The Smashing Machine, is about mixed martial arts, not wrestling. Where The Smashing Machine falters is in using that persuasive performance to say anything beyond the notion that pro athletes suffer terrible hardships that fans never see and rarely consider. Unlike the Safdies’ earlier films, though, The Smashing Machine never builds to any real sense of suspense or urgency about Kerr’s trials and tribulations. The Smashing Machine is sadly not a knockout. -The Smashing Machine is based on a 2002 documentary of the same name directed by John Hyams.