In all honesty, if someone were to try to "learn how to box like Roy Jones Jr." they wouldn't get very far for very long in boxing. RJJ was able to get a way with a lot of things that boxers would not normally do for the fact that he was gifted with an ungodly amount of speed and lightning fast reflexes.
Sure you can try to emulate his style, but unless you are as gifted as he is I doubt you'll get too far. It's like someone saying that they want to be able to play the "rope-a-dope" like Ali. You gotta' realize that Ali did that because he was Ali... Even then, he was only able to do it once.
Aspiring folks should see what the pros do, and understand that they need to learn all the basics before they even get that far. Otherwise, they might as well try to do a 800 meter swim in the open ocean without first learning how to float in the shallow end of the pool. Drowning is a messed up way (but higly effective if you survive) to learn a lesson.
It doesn't matter if you agree or disagree
... As long as I don't bore you and I spark a moment of thought, my goal is achieved
Queng leon queng tigre ecu tacacut, queca pa? - Pampangan Mandarigma Motto