Fischer was mentally ill. People don't seem to understand the ramifications of it. Anyway, I dont know who would have won, but I like Fischer.
Fischer vs Karpov

Fischer. But the USCF wilted when the Soviets refused Fischer's request that draws don't count.
It was more to do with the condition that "Fischer needs 9-9 to win, Karpov needs 10-8", but whatever helps you sleep at night I guess.

^ In many sports, more is demanded of the challenger than the champion. It's just the way of the world. But you miss the point: the USCF should have been by his side.
"In many sports, more is demanded of the challenger than the champion. It's just the way of the world. But you miss the point: the USCF should have been by his side"
More was already demanded of the challenger since the Champion had draw odds in the format that had been used since 1951, a format Fischer considered unfair to the challenger as long as he was not the Champion himself...
I have no idea what USCF thought on the subject, but Fischer's demand that the format should be changed to first to ten wins, draws not counting, was accepted by FIDE. What was not accepted was that Karpov would have to win 10-8 to become World Champion.
Karpov wasn't ready to beat Fischer in '75 in my opinion. He would have learned so much from that match however, just like Kasparov did against Karpov. Old thread resurrected by the way!

I have no idea what USCF thought on the subject, but Fischer's demand that the format should be changed to first to ten wins, draws not counting, was accepted by FIDE. What was not accepted was that Karpov would have to win 10-8 to become World Champion.
That's more or less what I said. If it went to 9-9 then the match would be ended and Fischer keep the title - which meant in practical terms Karpov had to win by 10-8 or better.
Quite why the USCF should have backed Fischer on this travesty I have no idea, unless it's really the case that they should back the US player no matter how silly the demands.

I've always been under the impression that the USCF never really threw their whole weight behind Fischer because they felt he was more trouble than he was worth, while Bobby - being a loner by nature anyway - liked it that way.
I wouldn't say I'm especially well read on this though, perhaps some of our American friends know more about this?

It isn't about how silly the demands are; it's about who is making the demands. Fischer was a member of the USCF, and America's brightest hope. The USCF existed to serve him. The fact is that the Soviets were in FIDE's pocket, and the USCF was afraid of them. I have a thread around here somewhere about my personal experience with this back in the day.
^ In many sports, more is demanded of the challenger than the champion. It's just the way of the world. But you miss the point: the USCF should have been by his side.
Usually the champion gets an advantage if some kind of tiebreaker is needed, but to demand that the challenger needs a two point lead to win the match is completely ridiculous.

^ Not out of 18 games, it isn't. Look at it this way: the champion begins the match with a win. That's it. Even in cooking competitions, like Master Chef, the champion gets this same advantage. So do NFL conference champions. Their challengers must win games for the privilege of playing the top dog. It's a simple and fair concept.

I think Karpov would have won. Fischer was inactive for 3 years and that's why he demanded a match under the conditions that he did. His intent was to beat the rust off and he knew Karpov was lacking stamina after observing the match with Korchnoi.
Fischer only could have defeated Karpov under those conditions. With standard conditions, Karpov wins.
Karpov was stronger in 1974 than Fischer was in 1972, which was the last time he played. With 3 years of inactivity, could Fischer possibly have improved? Now people please do understand what I am saying. I'm not saying that Karpov was generally the stronger player. Humans don't play at a consistent strength over spans of many years. Fischer was hot in 70 and 71 and by 72, he wasn't playing at the same strength. Anyway, there is just too much objective evidence that Karpov was already playing stronger than Fischer by 1974.
It is possible, though, that Fischer was stronger than anyone ever by 1975. He did previously go into seclusion once or twice and come back stronger.

Karpov was stronger in 1974 than Fischer was in 1972, which was the last time he played.
Not according to FIDE ratings. And Fischer always went through periods of inactivity and came back as strong if not stronger. And had the match been agreed to, he probably would have started training with some close chess friends, and that would have been enough to knock any rust off.
It's as likely that Karpov would never had become champion at all had Fischer kept playing, as it is that Karpov would have become champion in 1975. And I guess you could interpret "as likely" as "we'll never know"
^ Not out of 18 games, it isn't. Look at it this way: the champion begins the match with a win. That's it. Even in cooking competitions, like Master Chef, the champion gets this same advantage. So do NFL conference champions. Their challengers must win games for the privilege of playing the top dog. It's a simple and fair concept.
It's a simple and unfair concept, which is the reason nobody ever uses it in chess.
Btw: as far as I know, the NFL gives home court advantage to the team that played the stronger regular season, which is sensible and has nothing at all to do with Fischer's claims.

Many interesting opinions... The truth is that there is no answer to this question. Some people favour Fischer , others favour Karpov. How can we tell what would have happened???

Karpov was stronger in 1974 than Fischer was in 1972, which was the last time he played.
Not according to FIDE ratings. And Fischer always went through periods of inactivity and came back as strong if not stronger. And had the match been agreed to, he probably would have started training with some close chess friends, and that would have been enough to knock any rust off.
It's as likely that Karpov would never had become champion at all had Fischer kept playing, as it is that Karpov would have become champion in 1975. And I guess you could interpret "as likely" as "we'll never know"
Ratings NEVER catch up to "form." I shouldn't even have to explain this. You can compare Karpov's match against Spassky from 1974 to Fischer's WCC match in 1972. Go analyze it with a computer. One was a high quality match and the other was garbage.
Peak vs Peak Dominance is the only way to compare champions - Fischer= GOAT