Broadcasting Legend Bob Costas Leaves NBC After Four Decades Costas joined the network <br />back in 1979. He has called nearly every kind of <br />major sporting event for NBC for the last 40 years, including the World Series, <br />Super Bowls and the NBA Finals. According to Costas, his split with <br />NBC was amicable. Bob Costas, via <br />'The New York Post' The 66-year-old says he will still remain on the air with the MLB Network, calling baseball games from time to time.
