I'm sure that one makes sense in the American Mid-West, given sufficient beer and pizzas. Other than that, what exactly is going on? Maybe it needs fireworks.
I looked this up last time it came up: The 'sled' vehicle behind the tractor has a bulldozer style blade on the front, and a large mass that can move from front to back. This is driven by the wheels, so as it moves along the track, the weight shifts forward, causing the blade to progressively dig further into the ground. Therefore the distance the tractor pulls the sled down the track is an indication of how much pulling power it has.
No doubt at some point a bunch of hipsters from California will come along with a contraption based on a lead-acid submarine battery and the drivetrain from a several of crashed Teslas, win outright, and be hounded across state lines with pitchforks and pump-action shotguns for being homosexual commie vegetarians.