Eery one has 'hand speed' it's easy to throw a quick arm punch... when people talk about hand speed, like what ALi/Tyson/RJJ all have, those shots having something on them... it's about being able to throw a correct punch and more off it... through proper weight transfer... it comes from two things correct and natural technique and ability... and obviously the right genetics.

it's all in the shoulders and hips, when you see a fighter doing a public work out and they do the whole 'hurricane upper cut' thing when they spar... that's nothing... just elbows and upper arm movement.

Cus would make Mike Shadow box really slowly, focusing on form and exagerating his movements, it wouldn't physically develop speed, but it gave him the mental and physical muscle memory to be able to move that fast.

Thats why his foot work, head movement and shots where so fast and that's where the power came from.