...Phil Liggett and Paul Sherwen do the entire play-by-play. The evening "extended coverage" version is Trout Wig and Bob Roll, whom I like as a studio a commentator but he stutters alot during live action and is not nearly as fluid and eloquent as Master Phil.
Here's the trick: Tape the day times airings for Phil and Paul and tape the last 30 minutes with the Trout and Bobke for the addtional interviews during extended coverage. $0.02.