I'm sure these have already been posted somewhere but...
[ame="http://www.youtube.com/watch?v=qRvCCrCUuPM"]YouTube- John Smith v. Tom Brands 1991 US Open[/ame]
Smith vs Brands (1991)
[ame="http://www.youtube.com/watch?v=6jC_NSXkZiA"]YouTube- 1989 John Smith vs Sergei Beloglasov[/ame]
Smith vs Beloglazov
I know John Smith struggled somewhat in 1992. Not sure how much of that was due to ilness or something else that can be overcome, and how much was due to his body breaking down.... his physical health would probably determine how long he could have kept winning. I'm not sure there was anyone better then him at his weight- ever.