The "Battle of the Sexes" tennis match between Billie Jean King and Bobby Riggs is one of the most iconic moments in American sports history. Set against the backdrop of the women's liberation movement, King's 1973 victory over Riggs transcended sports. But a news tip from an unexpected source, 40 years later, sent ESPN's Don Van Natta Jr. down a path that led him to investigate whether the match was rigged. Van Natta details his reporting on the lead-up to The Battle of the Sexes, and how Riggs' own agenda may have impacted the historic outcome.