Top Ten Heavyweights Ever

I don't like to change my list too regularly... I prefer to rank the fighters based on a 15 guys tournament where every fighter faces all of the others in their respective primes. So, based on a 14 fight sample vs the other 14 fighters, my ranking goes like this :

1-Muhammad Ali (Fastest HW ever of hand & foot, tough as nails)
2-Joe Louis (One of the best p-4-p composite punchers ever)
3-Sonny Liston (Most physically gifted HW ever)
4-George Foreman (Heaviest puncher ever)
5-Larry Holmes (Well rounded fighter with legendary jab. Had balls)
6-Lennox Lewis (The best of both worlds, can outbox you or he can.. annihilate you)
7-Jack Johnson (A defensive genius and master feinter)
8-Mike Tyson (The best blend of speed & power ever. Vicious fighter but he was a bully who can be outbullied)
9-Jack Dempsey (The true definition of ferociousness. Fought like a tiger and showed no mercy)
10-Rocky Marciano (A small man made of granite)
11-Joe Frazier (The best hooker in the business. I think I may underrate him)
12-Jim Jeffries (difficult to rank. Was dominant in his prime, but he's a longer fight specialist. Could he beat the elite within 15 or 12 rounds ?)
13-Evander Holyfield (A warrior in every sense of the word. Could beat virtually anybody on any given night... or he could lose)
14-Riddick Bowe (A giant HW with power and impressive inside skills. Questionable traning habits)
15-Ezzard Charles (At his very best at 175 but nonetheless a good, mobile and talented HW)