There’s a moment early in the first episode of Netflix’s behind-the-scenes tennis show Break Point at which 22-year-old Costeen Hatzi, current girlfriend of the Australian ace Nick Kyrgios, laughingly admits that she has never watched a tennis match in her life. “This is all new for me,” she says. In this respect she is a mirror image of the viewer that the streaming service, and indeed tennis itself, wants to attract. Sports television has long been the preserve of dedicated fans, the kind of people who can reel off scores, records, statistics, and tend to be what James Gay-Rees, the award-winning British producer of Break Point, calls “a male, pale…