When characters in a movie watch TV, the producers can't just steal the sound of an actual broadcast. They're copyrighted. So voices are often recorded specifically for the movie. However, since the volume is too typically too low to actually hear what is being said, many of us consider this an oppportunity to have a little fun.
For the scenes when Sadie and Nelson are watching the baseball game, the voices of the announcers are actually Alvin Keith (the actor who played Nelson), Tony Mascara (our sound mixer), and Nicholas Gray (our writer-director). What they're discussing might surprise you! (Hint: it aint no baseball game...)