Ruiz has an edge in height, reach, huge edge in skills, quickness and boxing IQ. Tua hits harder and both have/had great.chins. I think that fat version of Tua that fought Lewis would be outboxed by Ruiz, but the best version of David (20 lbs lighter than he was against Lewis) would have had a good chance of catching Ruiz with a left hook in the exchanges.
No version of Tua was fast enough to win a decision against Ruiz, and no version of Tua was powerful enough to KO Ruiz. Keep in mind for a moment, that Tua landed flush, maximum-powered punches after maximum-powered punches on the following bum with literally a losing record: http://boxrec.com/en/boxer/219753 and that is to no avail. Never mind a knockout, but without even a single knockdown whilst barely even stunning that bum. Why? because unfortunately for poor little Tua, his power could not dent Demetrice King's durability. Guess what? Ruiz is just as big, at worst, just as durable and is significantly faster. If you can't even drop Demetrice King with multiple of your best shots landing as flush as possible, you don't even qualify as someone who can KO Andy Ruiz, irrespective of what punch you catch him with. So no, Tua ain't knocking Ruiz out, even in his wildest dream. And there's no way he can decision someone that much faster than himself. This fight goes the distance pretty much every-time and Ruiz wins it pretty much every-time too.
