Tyson's prime : 1986 , when he won the wbc title against Berbick and end of his prime when he lost all the belts against Douglas in 1990 , but still I think that Holyfield and Lewis were better boxers than Tyson . Even in his prime Tyson would have lost with them ( Holyfield and Lewis ).
This. Simply because he chose not to train for a particular fight and turn up with bad conditioning doesn't mean he was post-prime. On a linear, uninterrupted career trajectory he probably would've really shown significant decline in late '93-early '94. Going to prison saved him wear and tear, but added rust made him lose a good step or two. Many will point out that he became a crude one punch slugger after Spinks - and while he did use a lot less movement - he was still insanely dangerous for Bruno, Williams, Douglas (evidenced by still dropping Douglas out of nowhere) and both Ruddock fights. Very good, rated fighters with Ruddock being particularly dangerous at that point in time. Stewart and Tillman were rather insignificant exhibitions that he steamrolled as well obviously.