HeMateMe: Ali/Fischer parallels:
1. Prodigies, gifted as youths. Ali was an amateur boxing champion, skill and blinding speed. Fischer was, well, Fischer.
2. Early dominance. Ali wins gold medal as a light heavyweight, 1960 Rome Olympics. In 1960 Fischer is USA champion, already in the world's top ten.
3. Not afraid to speak their minds. Ali "The Lousiville [Kentucky] Lip" "I am the GREATEST!!"
Fischer: "When I win, I do it on my own. NO ONE helps me"
4. Polarizing effect on people. Blacks loved Ali, Many whites hated him for his swagger.
Fischer--greatly respected for his chess art, but disliked in the same vein because of his unflexible demeanor. Fischer's problem got worse, Ali became manageable, a harmless eccentric. Playful.
5. Both missed the Vietnam war--Ali by choice, Fischer--by political intervention?
6. Both have holes in their respective careers, disappearing at the height of their powers. Ali is banned from boxing 1967-70. Fischer takes a couple of years off in the 60s, when he should have been playing Candidates matches against Spassky. Disappears for good in 1972.
7. Undisputed world champions. Ali, in 1962, and again in 1974+. Fischer, 1972, and much of the 1960s, if only by public opinion.
8. An Ali fight wasn't just a fight--it was an event, a media circus. Only he had such power. Fischer--Chess jumps in global popularity, people come to a tournament, because Fischer is playing.
9. They both brought huge money into their sports. Ali's purses were much bigger than what boxing had seen before. $5M for one fight. Fischer turned chess from a sport for hobbyists to a big money sport for the very best.
10. Sad end. Ali has Parkinsons, possibly the symptoms are exacerbated by the beating he took in a pro career that lasted 20 years. Fischer lost touch with reality and died an outcast, unwilling to let modern medicine help them.
11. They both met the Beatles, and...Oh, wait a minute. Ali met the Beatles, when they were down in Miami, and Ali was training there. Still, if the fab four had any sense, they would have known Fischer was special and sought him out when they were in New York City. They must have had at least 20 minutes where they weren't booked to do something; they should have had Bob come over to their hotel room, chat on Marvin Gave v. Little Richard. I'm sure Fischer would have had an opionion on popular music. Shame on you, Brian Epstein.
12. Oh, religion--both are somewhat known for religion + controversy. Fischer and the Herbert Armstong Church of God, or whatever it was called. A carnival huckster. But, he reeled in Fischer. Perhaps his biggest Fish, no pun intended.
Ali of course, joined the controversial Muslim religion championed by Malcom X. Joining the church of Allah and changing his name brought Ali many enemies, among both whites and blacks. Malcolm X is killed, probably in a power struggle with a follower (elijah Mohammad?) who wanted to be top banana. Ali wisely stays out of the power struggle.
13. Fischer boxed in the Catskills, to get in shape for his 1972 match with Spassky. He knew boxing was great cardiovascular work, the speed bag and the heavy bag (not sparring) Reciprocal? Well, I don't think there are any instances of Cassius playing chess. He relaxed by having sex with the unending flow of women who presented themselves before him, 24/7. This isn't really covered by historians, but Ali was as busy with the opposite sex as was JFK, the media just didn't cover this aspect of life they way they do now. This is more an Ali/JFK parallel, so we'll just strike this one.
There are more similarities, but that covers the main points. Truly, 'Mo and Bob are two of the giant personalities of this era.