Y'know, 19 year old Mike Tyson had been a pro for only 8 months when Cus D'Amato died in Nov 1985.
The first time I ever saw Mike Tyson was on tv the month after, Dec 1985, the Big Sam Scaff fight, and Tyson looked amazing. It was his 14th fight in only 9 months as a pro. They had him fighting 2 fights each month, sometimes even 3 in a month.
They were developing Tyson, so the opponents were low-level yet, but as the level increased, the knockouts kept coming right up to the world-class level less than a year later. He was demolishing them.



Phenomenal fighter in 1986, '87, and '88.
I think his accomplishments earns him a position in the Top 10 Heavyweights of All-Time.
Youngest Champ of All-Time.
He unified the division and restored order as there were 3 Champs at the time.
Next he restored lineage by capturing the lineal Man-Who-Beat-The-Man title by KO'ing Michael Spinks in '88. Tyson also was #1 on the Pound-For-Pound list.
Dominant fighter for a few years. Everyone knew who was The Man, there was no debate.

^ That's enough to earn him a spot.