Top 10 Heavyweights in History?

Excerpt taken from the book, Uppercuts:Tales from the Ring, by George Thomas Clark ($0.99 ebook or 73p from kobo books, not sure what to make of such a cheap book)

I don't do all-time rankings but not sure if I did a list it would be like this one, but what would I know?

His list:-

1. Muhammad Ali
2. Larry Holmes
3. Lennox Lewis
4. George Foreman
5. Joe Louis
6. Joe Frazier
7. Mike Tyson
8. Ken Norton
9. Sonny Liston
10. Jack Johnson

Top Ten Heavyweight Champions - Boxing.com