Do you of any fighters who didn't last as long as the could have due to having too intense sparring sessions?
Not really what you're asking for I think but Muangsurin's eye injury in the late 70s, reportedly suffered in sparring, ruined him.
I wouldn't say he burned out early, but I think James Toney would have clearer speech today if it wasn't for his training camps that consisted purely of sparring. There's no reason for a defensive wizard like himself to have any kind of brain damage, even with the hits he's taken in his later career. He has around the same amount of pro fights that George Foreman had (who got hit wayyyy more with alot more flush shots than Toney) and Foreman has zero signs of brain damage.
Mike Quarry is a great call. I got to watch him spar with Jerry and it was brutal. He took some unbelievable beatings from his brother of all people. Its sad and sickening to think about particularly in light of how they both ended up.
David Reid was injured by Daniel Santos in the Pan-Am games, moved quickly, and suffered a separate injury as well as exacerbating his bad eye against Tito. Those were his main problems I'd say. Andy Lee was never very good IMO. Rate based off that K.O and hype from Manny Steward. He was as stiff as a board, awkward under fire, not very durable and only sporadically got his **** together. Above average at best and I'm being generous there. I like him though.
Right, but his pattern of speech always seemed a little off to me and he's suffering from depression now. Maybe those are related to gym wars, maybe not.
Was a tearaway youth by all accounts so maybe he wasn't just that good a talker? Not that those things are inherently linked but it's a thought. Just as likely as general wear and tear. No need to link it to sparring wars unless you've got a quote or something to go on, although of course taking any punches will take brain cells.
Meldrick Taylor Joe Frazier (FOTC really was the defining point though) Ali's sparring habits of letting his sparring partners get shots in on him couldn't have helped his current condition.
Curtis Parker is a great shout. He was known for routinely taking on men much taller and heavier than him and going all out.