Forbin you are correct.....Costas became a baseball fanatick during those years....he claims to have honed his broadcasting skills by turning down the volume on the Sat. Game of the week with Tony Kubek and Joe Garagiola; he then called his on play by play in his room.
This is a cool and true story....I was in St. Louis in 1993 after the Series was over, I was at Tony's on Market Street dining with the ex-wife; sitting at the table to our right was Joe Buck and his dad Jack, to the left was Stan Musial and his wife. Musial was a hoot, he did the nappkin trick where it turns into a bra. Across the room was the actor from Quantum Leap...I can't remember his name. Anyway, good eats in St. Louie...especially on the Hill.