It's difficult to say different between good punch or not, but most of the time punch we don't feel power is good one, punch we feel power is not good, because of punch is the one we have to through, don't need muscle of arms or chest so much, that's why chin down, elbow in, balance low, keep legs moving is very important for Boxing, that makes flow of the punch, that is kind of relay of whole muscle, it get started from legs, anyway his left hook looks good I use another way but, right hook not so good, I mean that's different from left, of course I respect his Boxing.