When COVID told us we all needed to be six feet apart, some people became addicted to TikTok and other people picked up a racket. Since 2019, tennis participation in the U.S. has grown by 54 percent. And that's excluding all the avid pickleball lovers who keep stealing their courts. So, why are we just becoming obsessed with a game that Andy Roddick has been obsessed with his whole life? Kal talks to the former number one player in the world about why and how his sport is making a comeback.