How does RunnerBeam decide the winner and the assist?

In an uncapped race, the last athlete still standing once everyone else has retired is named the winner, and the retired athlete who went furthest is named the assist. If several athletes fell on the same yard, they share the assist.

If you set a maximum number of yards, that cap is the finish line: every athlete who completes it is a finisher rather than a single winner. In both cases race control ends the race by confirming the final yard, and the race clock closes at the end of that yard.