Why do you say Hopkins? BHop had speed, and power from the get go, developed later into a better technician. btw when i say power, i mean 1 hit quit power.
Dwight Qawi had no amateur career, learned to box in prison, and was half a foot shorter than a lot of the guys in his division.
Dwight Muhammad Qawi is another good one, especially since he was such a small dude. But I think Marciano is one who achieved the most with the least talent and athletcism. He was routinely beaten even when he fought in Army matches where he was ridiculed as the "Brockton Human Punch Bag".
How so? Hopkins always had solid athletic ability and coupled that with work ethic and developed his Ring IQ through great study/preparation. I think he just made the most of his talents, of which he was plentiful. Not like he had to overcome deficiencies.
Completely forgot to put Librado Andrade in this. Doesn't look fast, has terrible defense letting people hit him constantly, isn't particularly skilled. Has a mountain of heart, great endurance, and good power...just pressures the hell out of people.