I saw several of Shavers' fights, including his fight with Ali, his fights with Holmes, his debacle against Quarry and his knockout of Ken Norton. The thing that made Shavers such a hard puncher was the effort that he put into his power punches, particularly his hooks. Shavers was by no means a big heavyweight at 6'1" and weighing in the neighborhood of 210 lbs. but he got incredible leverage from his shots.

In a different thread I used this analogy: Imagine that someone really makes you angry but you're not in a position to do anything about it. For example, your boss belittles you openly in front of several others without warning and without checking out his facts carefully. You feel like killing the guy, but you just have to take it and bide your time. You go home and go into your garage where a heavy bag waits, and you decide to pretend that the heavy bag is your boss. You grunt loudly as you put everything you have into a few shots against the heavy bag. That's the way Earnie Shavers threw his hooks. I ain't kidding!