How Did Matt Weiters Learn to Call a Ballgame?

According to Baltimore roving catching instructor Don Werner ...

He told me he and his dad would always watch the Braves play and watch the three big pitchers —Greg Maddux, John Smoltz and Tom Glavine ... He and his dad would go over a game: 'What would you call here? What would you call there?' The interesting thing is you had a right-handed control pitcher in Maddux, a left-handed control pitcher in Glavine and a power pitcher in Smoltz, so three different approaches to the same hitter, and they'd discuss the game that way.