[Tom Line]

A very simplified and perhaps more accurate version of over/under (and closer to the NHL version) would be to simply take your team score and subtract your opponents score.

This would, of course, be subject to issues around teams scoring on themselves to prevent to large a win, but it would certainly still be valid considering how rare that will be.

In NHL, it's not your personal goals vs. how many is scored on you - it all goals scored while you're on the ice by your entire line... very similar to this situation.

So you only need to grab the final scores and the robots involved in each match to calculate it.