It's been said that winning a world championship can take a fighter to a different level than they've been to before with the confidence that they gain from being a world champion. Which fighters hit their peak years when they won the title and then descended irreversibly as soon as they lost it?
"Big" John Tate... Beat Gerrie Coetzee for the Vacant WBA Title (2-Belt Era), After Coetzee Wiped His Ass w/Leon Spinks in LESS Than 1 Round...Beat the Brakes Off Mike Weaver in His 1st Title Defense, Only to Get KO'ed w/45-50 Seconds Left in the 15th Round.... Tate PEAKED @ the Point of Beating Coetzee for the Vacant Strap and was NEVER the Same After Squandering a FOR SURE Win Over Mike Weaver in the Waning Seconds of that Fight... Believe it or Not, John Tate Was Held in HIGHER Regard Than Larry Holmes, Up Until the "Hail Mary" Mike Weaver KO.... REED
Miguel Lora Tyson is a good mention. I think Olivares true peak ended around the time of the Castillo rematches.
Probably true about his absolute peak but I wouldn't really consider him as he kept winning titles after that.
Pipino Cuevas had a spotty record and then went on an awesome KO streak when he won the title. The crushing loss to Hearns ended him as a force after that.
Possibly, although I think his post-Olivares struggles resulted mainly from fighting at a higher weight where he was less effective and more vulnerable to big punchers.
I tend to think that fighting such high level opposition while struggling to make weight at such a young age burnt him out. Taking an ass-whupping like the one Olivares gave him while drained can't have been helpful either. But I agree, him fighting at a higher weight may have made it seem like he was further past his best than he actually was.
Tyson, Curry, Cuevas immediately come to mind. Although, Mike was a lot formidable post-title than Curry and Cuevas.