Anybody remembers Ray Robinson throwing left jab immediately followed by straight right? I remember only him throwing either a right hook or an uppercut after a jab, but never a straight right.
Not off the top of my head, I don't. I do remember the triple left hook combo he used to throw, however.
What could be the reason for this? May it be because of the gloves used in those days that they don't provide enough protection to the fist, and with straight right it's easy to hit the forehead or top of the head instead of the jaw or temple where a punch should be aimed?