HBO

(A brief aside: The book — by Jeff Pearlman, a longtime sportswriter — and era are both called “Showtime,” which would have been a perfect title for the show in about four different ways, and there’s even a point early on where a band performs a song with “showtime” in the chorus, but the show is called Winning Time because it is on HBO and Showtime is quite literally the name of one of HBO’s biggest premium cable competitors. This is very funny to me.)