The 2 worst chins in heavyweight boxing but WHO has the worst ? Rahman who has been KTFO multiple times including getting knocked into row Z or Fraudley who got knocked out by non-event non-puncher Michael Sprott who wasnt even looking when he "left his arm out for Audley's head to hit into". Rahman http://www.youtube.com/watch?v=tQeqquW1ugo Fraudley http://www.youtube.com/watch?v=NmjzFTJMjzo
Harrison. Rahman may have been stopped a few times, but a) his level of opposition is far greater and b) lewis & wlad were two of the guys that did it. Those two guys would get rid of Harrison and Sprott at the same time within a round.
Substitute Rahman for Harrison in those fights..... It either doesn't happen through Harrison running, or doing a Gary Lockett..... Or it happens much quicker and brutally.
I don't think Rahman's is as terrible as its made out, I'd say Harrison due to competition levels, and also the fact Harrison fights like a scared man and keeps his chin well out the way. If you dug a little deeper there will be worse heavyweight chins out there. I don't think David Haye is taking a good crack from anyone, if we're talking only "decent" fighters.