One of the best Heavyweight left hookers was Tommy "The Duke" Morrison. He would pivot perfectly into the punch, his mechanics were perfect for that punch.
You're welcome. Pretty much exactly that. Ruskull is right. Try hitting a heavy bay whilst just using your arm. It's **** basically. An arm punch is a punch thrown without the body behind it. A true punch uses the legs, lats and core to provide the power. An arm punch is a punch that uses predominantly the shoulder, triceps and biceps to provide the power, almost inevitably leading to a 'weak' punch. Powerful punches come from the legs and core and then driving through the target. weak punches come from the arm alone which carries relatively weak muscles compared to the rest of the powerful, full body muscles.
It's just Vitali's style as orriray59 has said. A guy who weighs 250lbs can sometimes get away with throwing arm punches and still cause quite a bit of damage. Vitali tends to break guys down with arm punches. George Foreman sometimes threw arm punches and because of his physical strength, specifically his arm strength, they were still devastating. But Foreman (one of the hardest hitters EVER) was a freak of nature. Generally, for most boxers, arm punches are just not as effective.
Yeah man. Foreman is one of the strongest men, alongside perhaps Sonny Liston, I have ever seen in the ring. He often looked like he really couldn't be bothered and just flicked his fist at his opponents. Yet down they went. Out cold. Foreman was a beast.