Prime RJJ's weaknesses.

[Sleepwalker]

Have problems with guys who fought awkwardly and had big punch and length so most likely i see Spinks owning that fight. Not to mention Spinks was undefeated at the weight and was not even put down in a lhw fight Roy is up there though only Foster and Spinks are ahead of him. Also he would never have the best longevity because his style pretty much all had to do with his reflex and speed which is the first to go with a fighter. I mean all you have to do is look how he aged when he lost his speed he was ok fighter so he went from great to goodish faster then those fighters that learned the craft.

Which makes Ali's achievement even greater because after his reflexes eroded he had to rely on his chin, courage and wit. Roy just collapsed.

Ali developed an amazing blocking technique during the 2nd half of his career (early 70s in particular) after his head movement diminished. He practically shelled his entire upper body.