The new cover of Sports Illustrated declares that fighter Ronda Rousey is “the world’s most dominant athlete.” Rousey is definitely one of the most high-profile sports stars on the planet, with a role in the coming movie “Entourage,” a new memoir titled “My Fight/Your Fight,” and her ongoing reign as UFC champion.

Wall Street Journal readers who want to see Rousey live will get a chance on May 20 when the mixed martial artist stops by the WSJ Café in Los Angeles to chat with me and WSJ sports columnist Jason Gay about her...