Re: Pugilistic dementia...
For the people mentioning Benitez, I think more of that came from him being hit a lot while he was still young. i mean hell he was a world champion when he was 17. His dad used to put him in the streets with older kids and bet on it. I think if you take a lot of punishment before your brain fully develops then it greatly increases the risk of dementia later on down the road. Same with some of these guys who had 200+ amateur fights and do a lot of sparring in their teens.
Then there are the fighters who just stay in the game too long and the last 3,4 fights really mess them up. That extra sparring and getting hit solidly those extra 2-3 years really makes a big difference. How much different would Ali have been if he would have retired in '76 instead of fighting those last to years when he was washed up. Another one pointed out the gym wars...and two that really come to mind are Meldrick Taylor and Terry Norris. Both of these guys became very slurred during their careers. Taylor was a product of the Philly gym wars and Norris reportedly would spar 12 rounds 2-3 a week in preparation for a fight! I mean that is a shit ton of sparring leading up to a bout. I know a lot of the old timers would only spar 3 weeks before the fight in to stay sharp and get their reflexes and timing down. But like somebody pointed out, it all depends in the person.