Fischer vs Karpov

What about Karpov? Let’s remember the fact that Fischer had not played a single game since 1972, whereas Karpov had just done a legendary streak in 1974, beating Polugaevsky, Spassky and Korchnoi. Also, Fischer frequently analyzed obsessively alone, but no amount of obsessiveness can beat the entire Soviet team that was helping Karpov, who were also quite obsessive. Finally, Fischer’s mental health had deteriorated immensely, and by 1975 he was perhaps too erratic and mentally unstable to finish a high-stakes world championship. So why would Fischer really win, or would Karpov actually win?

"Fischer had not played a single game since 1972"

• Fischer had not played in 1969 either, and yet he came back stronger than ever in 1970.

"beating Polugaevsky, Spassky and Korchnoi"

• Fischer had beaten Taimanov 6 - 0, Larsen 6 - 0, Petrosian 6.5 - 2.5, and Spassky 12.5 - 8.5 practically giving 0-2 odds.
  The 1974 Karpov - Korchnoi match was fixed: Korchnoi believed he would lose to Fischer and threw the match to Karpov in exchange for 2 tournaments abroad.

"no amount of obsessiveness can beat the entire Soviet team"

• The entire Soviet team was available for Taimanov, Petrosian, and Spassky.

"Fischer’s mental health had deteriorated"

• That is slander.

"by 1975 he was perhaps too erratic and mentally unstable to finish a high-stakes world championship"

• He was erratic in 1972 hesitating to play or not, blundering game 1, forfeiting game 2, and won nevertheless.

@tpr said ^

The 1974 Karpov - Korchnoi match was fixed: Korchnoi believed he would lose to Fischer and threw the match to Karpov in exchange for 2 tournaments abroad.

Utter bollocks.

Geller or Korchnoi might've actually made Fischer sweat. Taimanov? He basically played right into Fischer's hands.

"Geller or Korchnoi might've actually made Fischer sweat."

• Geller had a good record +5-4=2 against Fischer, that is why he served as second of Spassky in the 1972 match against Fischer.
  However, Spassky had an even better record +3=2-0 against Fischer before their 1972 match.
  Korchnoi thought he would lose to Fischer.
  That is why he threw his 1971 candidates' match to Petrosian in exchange for 3 tournaments abroad, and his 1974 match against Karpov in exchange for 2 tournaments abroad. He expected Fischer to defeat Karpov. However, Fischer did not play because FIDE rejected his 9-9 clause, and so Korchnoi had thrown away his chance to become World Champion. Korchnoi then used the promised 2 tournaments abroad to defect to the west, leaving his wife Bella and son Igor behind in the USSR.

Fischer

Before the match vs Spasski, quote by Donner:

"... it doesn't take much insight into human nature to predict that Fischer will not be world champion for long. His quirks, moods and whims will turn against him at the moment when he has reached the top. He'll hit out hard, but at nothing but thin air.„

Fischer had a short sprint, and it was not even as glorious as some of his fans make it out to be. Here are some objective facts:

He became World Champion just once.
His opponent, Spassky, was in one of the worst periods of his life during the match, with his second marriage on the verge of falling apart, putting tremendous pressure on him and his public persona.
Efim Geller, though a very strong legend of the game, was not the best player in the world, yet his total score against Bobby Fischer was 5 wins to 3 losses. You do not need to put him to test against Karpov. Just strong GM of today can beat him
Even some of Fischer's best winning games, when submitted to Stockfish, are riddled with inaccuracies.

Lichess makes the analysis easy for you in this link.

"some of Fischer's best winning games, when submitted to Stockfish, are riddled with inaccuracies."

• The same with Carlsen, or Kasparov. The Sherwin game is from 1957, when Fischer was 14 years old.
  If you want to scrutinize his games, then please take games of 1971 - 1972.

"He became World Champion just once."

• He beat Taimanov 6 - 0, Larsen 6 - 0, Petrosian 6.5 - 2.5 and then Spassky 12.5 - 8.5 after starting 0 - 2.