Talk about Complete Savages! Kevin Arnold (Fred Savage, The Wonder Years) battles Cory Matthews (Ben Savage, Boy Meets World). Who will teach the other a valuable life lesson about the value of getting your ass kicked?
They are of roughly the same height and weight, so this comes down to the narrator factor. Kevin is required to pause for long stretches so that his future self can talk about what's going through his head and what he's learned. This will give Cory an opportunity to kick him in the teeth, and then go to Mr. Feeny to learn something. It always helps to get your lessons after the fight, rather than during, so I give a slight edge to Cory.