can you tell me which punch you saw him hurt someone moving backwards. to answer your question what hurts guys more than anything in boxing is shock. what most causes shock is not seeing the punch. what most causes not seeing the punch is turning or running into it. this is why counter punches are responsible for most of the knockdowns and knockouts you will see in boxing. which is to say, a guy will throw a punch, turn and run into a counter punch, not see it, and get shocked.
i have my own theory about this. i think that when many guys throw a punch their eyes will lock onto what they are trying to hit. so for example, their eyes will lock onto the head before they throw a punch to the head. chris byrd was a good example of that.
byrd used to have a trait where he would lock his eyes onto a guys head before throwing a string of punches living up to his nickname of rapid fire. so when he locked his eyes before starting up one of his rapid fire string of punches, he had a tendency to not see that a guy was also throwing a punch at the same time as him, causing a lot of shock if he got hit at that moment.
that was how he was knocked out by ike ibeabuchi.
look at byrds eyes again here. his eyes are locked onto the head to punch and he cant see the uppercut ibeabuchi is throwing. i believe this is what happens to many boxers.
when people are taught how to juggle they are taught to fix their eyes somewhere directly above the objects they are juggling and to see each object they are juggling with their peripheral vision instead of looking at each individual object directly. i think the same principle is probably true in boxing. when you lock your eyes onto the head before you throw a punch to the head, you will momentarily lose sight of the whole picture, putting you in a very vulnerable position while you punch.
my own theory is guys who are said to have good chins in boxing are actually in possession of a heightened awareness which allows them to be less shocked by punches than guys who lack this special awareness that they possess. they have a special ability to sense the punches and prevent shock which also means guys who are less sharp and less aware will be more prone to shock as a result of having or not having this ability.
some other factors for power include placement of the punch. you will see punches to places like the forehead cause less knockdowns and knockouts than punches to the jaw. some punches will be grazing and not flush. one of the biggest reasons for a punch not having power is it will not have any follow through. follow through is when a punch goes all the way through what it is hitting. so on that condition, this is good follow through.
you can see the punch continue all the way through the head here. but in boxing you will see guys throwing many times punches with poor or even no follow through at all.
by all conditions, this is a good right hand and possesses all of the mechanics a good right hand ought to have. but even the best thrown right hand must still be able to land with good placement, flush not grazing, and with a lot of shock. which is to say, power is nothing if it cant be set up properly.