In the old days this was called the right cross, because it "crossed" over an opponent's jab. You slip inside his jab and throw a right hook to his chin. Tall fighters have an advantage there, maybe, but an opponent has to jab up at a taller guy, making the punch harder to land unless you create angles. Many shorter fighters have had tremendous success with this punch because their opponents tend to jab down at them, leaving themselves vulnerable to this punch as they lean into it.