Helios727: In a book by Robert Byrne about the 1974 candidate matches, he made the following comments before covering the Korchnoi-Petrosian games:
"With the quarterfinals over, I thought this would be the easiest contest to pick--it had to go to Petrosian because of his calm, steady temperament, so beautifully adapted to match play. Korchnoi, on the other hand, could only damage himself by his risk-taking style, so much better suited to tournament play."
"But in making my prediction, I could not guess that Petrosian's opening play would be so inferior to Korchnoi's. Korchnoi did not experience his usual difficulty with the white pieces, but pressed a strong initiative in games 1, 3, and 5. Only once did Korchnoi let his guard drop (with Black) and his punishment did not affect the outcome of the match."
"Korchnoi's three wins were one less than the four required to win a semifinals match; he gained the victory when Petrosian pleaded illness after the fifth game. However, whether Petrosian suffered a genuine physical malady is open to question."
"What is certain is that the match was steeped in animosity from the beginning. In the first game Korchnoi roughly complained to his opponent about his habitual nervous foot tapping that sent vibrations to the surface of the chessboard. Petrosian lodged a written counter complaint to the referee about Korchnoi's disturbing him during the game (presumably Petrosian meant Korchnoi's speaking directly to him while the game was in progress--that's against the rules, except to offer a draw)."
"Matters came to a head in the fifth game, when Korchnoi, making reference to opponents who could find no fair way to win, again angrily complained about the foot tapping. It was probably the vigor of this repeated accusation, not to mention Petrosian's minus score, that led to his resigning the match. Will Petrosian turn up next time in carpet slippers with sponge-rubber soles?"