If Fischer would played Karpov for the World Champion, who would win?

I like both players and learned a lot from Fischer and Karpov but if a match took place in 1975, I believe Fischer would win. Fischer with his aggressive and dynamic style would been too much for Karpov. Karpov was leading in 1974 Candidates Match against Korchnoi but choke and Korchnoi was able to win and even the score and Karpov won the last game. The final score was Karpov 12.5 and Korchnoi 11.5. Too close and if Karpov had a difficult time with Korchnoi, can you imagine Fischer who is even more aggressive.

Was Fischer more aggressive than Korchnoi? Both were pretty aggressive.

I'm yellin' Fischer 'till my throat is raspy.

Fischer would win a long match, hands down.

Fischer claim to study all Anderssen's games, maybe this how he achieve his aggressive style. I include one of Fischer's game.

 W: Carl Grossguth vs.B: Bobby Fischer  US Junior Ch.1956

One of the reasons why Fischer demanded a long match (10 wins, unlimited number of games) was that he knew he was very rusty, having not played a single serious game in three years.  He needed time to get back into "playing form."

But yes, Fischer in '75 was almost certainly stronger than Karpov in '75.

1978 was a different matter however, and is open to more debate.

In 1978 against Korchnoi, Karpov had another close match, the final score was Karpov 6 wins, Korchnoi 5 wins and 21 draws. I believe Fischer would of won in 1978 too.

If god was god, what would he do?

Bet $100 on Fischer.

I like to include two more games of Fischer, so you can see before he became a GM, he had a deep understanding of chess. And the one with Saidy he was already a GM.

Dr. Saidy is an IM (1969) and a retired medical doctor.  He was a fixture in southern California chess for years.  He was a strong player who was rated in the mid-2400s (pre-inflation) at the peak of his career.

Pre 1972 Fischer would win

Post 1972 Fischer would lose

After winnng the title, Fischer just sorta lost his zest for the game. 

Nope.  He studied every Karpov game, guaranteed.

http://www.cbsnews.com/news/from-the-archives-bobby-fischer-in-1972/

Karpov with his positional understand and great endgame technique, his play is similar to Capablanca. Include three of his games.

W: Vladimir S.Kirpichnikov vs. B:Anatoly Karpov

Oh Bobby, how we miss ye.

Karpov's narrow wins against Korchnoi are often mentioned as a reason that he would have lost against Fischer, but Fischer didn't have a plus score against Korchnoi himself. One could just as well say that Karpov's scoring better against Spassky than Fischer did means that he would have beaten Fischer. Such comparisons are difficult to make though, Kasparov had 15-0 against Shirov, who won the Candidates match against Kramnik convincingly. Still Kasparov lost to Kramnik. Hard to say how Fischer would have done after three inactive years, but he just wasn't interested in playing chess after 1972.

At The National Open in Las Vegas (June 2014) I asked IM Saidy this question and he indicated Bobby would have won.  In part he said "Karpov may have had a team of 12 Grandmasters providing him variations, but Bobby was locked in his hotel room figuring them out for himself!  What does that tell you about who was stronger."  I may have a word or two wrong in the quote, but I agree that Bobby was a psychological killer in the form of a chess maniac, and would have destroyed Anatoly.

Boris Spassky said Fischer would have won the first match, but Karpov would win the next candidates and beat Fischer next time around.

I take Spassky's word over EVERYONE

It looks like 50/50 in that match, I read many times in books references as for Karpov's and Fisher's achievements against Spassky, but it's really impossible to say who would have won. In any case it's a pitty that the chess world was deprived of such an intriguing chess event - that match would have been extremely interesting. And it's still more pitty that Bobby is not with us now ...

Morris_7, I agree that Korchnoi is no pushover but Fischer would of been too much and Bobby would of destroy Viktor. I post a game of Fischer winning a fine game in the King's Indian defense.

I like to add Fischer Fide rating was 2780 and Korchnoi 2690, I don't think Viktor had a chances to win the title from Bobby.