What are the key factors in who wins this Super Bowl?

2 high powered offenses with great QBs. I think just like the NFC championship game and the Cards packers game; it will depend who scores last.....Or turnovers......Or a QB injury for both teams will implode if losing thier QB. I think these are the factors in who wins. But if turnovers are low and no injuries, I really believe who scores last wins.