I don't think it's possible to come up with a system that accomplishes what we're trying to accomplish, until we're clear on what we're trying to accomplish. And this sentence suggests to me that we aren't.
Someone may indeed be equally confident that we'll beat Bowling Green and UVA, but if they have different expectations regarding the score differential, then their confidence is likely not persuasive to someone with different intuitions. What we're trying to measure isn't whose irrational confidence happens to be correct across a tiny data set, but whose knowledge of football leads them to predict most accurately what the future holds.
So I would say that if you believe GT will beat UVA by a tiny margin, your confidence in the victory cannot be high. (I would also say you're a very young Tech fan if you're confident of any victory over UVA, but that's a different thread.)