I have seen every episode several times but there is one that I always have seen just part of. Can anyone tell me which episode has the Bradys with a dunking machine in their back yard???? Thanks!!

That's from the episode, My Sister, Benedict Arnold.

Greg is furious because Marcia is dating Warren Mulaney, the guy who beat him out of the first string basketball team. To make Marcia jealous, Greg starts dating Kathy, the girl who beat her out at cheerleading. In a side story, a carnival at school, has the Brady's getting the dunking machine ready for operation. In the episode, Bobby, Cindy and Alice each get dunked.