Kiddo is right about the uppercut from a tactical perspective. I also think it is best suited to inside, close fighting..WHAM!Power from the ground up..
I see amateur fights where people telegraph the uppercut so bad it becomes basically useless because even a slower fighter can get out of the way.
Close, inside fighting with your back against the ropes, best time to land an uppercut.
Razor Ruddock had a punch he was known for he called 'the smash' which was like a combination hook-uppercut. He destroyed Michael Dokes with that punch; but he almost always telegraphed it and was really only able to land it with full effect if he already had his opponent stunned first.