Originally Posted by Butch Coolidge
Watch how his weight is balanced. If his head is over his right, his weight is on his right so anticipate him throwing a right. Keep your guard up and be wary of his jab, the nonleverage punch, but being aware of his heavy artillery is coming from will keep you safe.
This maybe be true in very early amauteurs (aka, haymakers), but from more experianced boxers (6months+, depends on boxer) you will get destoryed if you follow this advice. If you throw punches/combos by tilting your body in one direction or another, that is called bad technique (unless of course your rolling off the punches and countering). Especially because proper punches are thrown by rotation of the hips and shoulders.
Factoring in feints and different styles of boxing, it's just best to stay on your toes, don't hesitate, and watch for the tells. After a few months of sparing and training you will eventually get to the point where you body will be able to tell which punches are being thrown and move on its own.
And I don't know what your talking about calling the jab a nonleverage punch. The jab can be equally as deadly if not more deadly than the right hand.