Tracing the roots of the pro-MMA league back to its tumultuous first event in 1993, UFC 1: Origins explores the improbable tale of how Rorion Gracie, a Brazilian jiu-jitsu specialist, and Art Davie, once a used car salesman, teamed with Bob Meyrowitz’s pay-per-view company SEG to mount UFC 1 in Denver and launch a sports phenomenon.