Dempsey had a longer career than people realise. He was a saloon fighter as a hobo, competing in underground prizefights for years before officially going pro. The Dempsey we saw fighting Tunney had a lot of mileage on his clock. His win over Sharky is proof he was still a good fighter, but on top of age and a long layoff I just think Tunney had a number on him. I’d add Jim Jefferies, to an extent Johnny Tapia, Jack Johnson and Max Baer. Marciano seemed to decline pretty fast before he retired. Ray Leonard’s second comeback was pretty suspect, Hagler win was controversial, Hearns rematch an outright robbery. Let’s not forget Ali’s three year exile.
Michael was nice, but his power was overrated, and I think reading something about his heavy drug use really began around 1982. Sad but true.
Maybe what he was shot dead for might have been part of the reason he didn't win the belt back then as well.