Left Hook
The Left Hook is one of the most devastating Power Punches. Boxer Joe Frazier was known for his Left Hook, and he floored Muhammed Ali with it. Another Boxer, Gerry Cooney had a Left Hook that not only KOed opponents, but would break bones when it landed.
In Mixed Martial Arts, headknocker Junior Dos Santos throws a wicked Left Hook that has Knocked the lights out of several of his opponents.
The are several reasons why the Left Hook so effective. One is because of the power generated in the mechanics of the Punch. The whole upper body rotates behind the Punch. But the legs, and hips generate the torque that sends the momentum to the upper body.
Another elemate of the Left Hook is that it's a stealth Punch, since it comes in from the side, and it's a short, quick Punch. This makes it hard to see coming, and you don't know it's enroute until after the damage is already done.
And finally theres the location of where the Left Hook lands, either on the right side of the jaw from a head Punch, or if it's a body Punch, a lot of pain can be produced by a Left Hook to the ribs. And it punishes the body, and wears opponents down.