"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)."

http://www.chessdryad.com/articles/...

<I wish to print the true facts of the tremendous Petrosian-Korchnoi match earlier this year, a match that shot Korchnoi into the top three players in the world. Though the real story has been suppressed by all U.S.S.R. media sources, there were so many Yugoslavian and German witnesses that we now know that a verbal war rather than chess ended the contest!

Korchnoi played beautifully to achieve three wins, one loss, and one draw in the first five games against Tigran Petrosian in Odessa, April 12-24, 1974. Just after the fourth game Tigran Petrosian went to the match committee and requested in writing that Victor Korchnoi be asked not to move his leg up and down beneath the table so much! It was just a Korchnoi nervous habit and did not seem to disturb anything really. No noise or offence intended probably. But Petrosian mentioned that Korchnoi had actually kicked him beneath the table while reaching out to make a move. Surely it was an accident....

Korchnoi knew absolutely nothing of Petrosian's complaint throughout the night, and it was only upon arriving for the fifth game that he was shocked by the formal request to quit moving his leg in a kicking motion beneath the table! Korchnoi was furious but did not say anything to his opponent, beginning to make moves against Petrosian in the fifth game.

You're not going to believe what happened next and at the worst possible moment. Petrosian, while shifting in the chair to adjust his hearing aid, kicked Victor Korchnoi accidentally! As match officials looked on with complete horror and silence. Everybody knew the match could explode any second.

Agreed--it was most likely a subconscious nervous habit, but as noted by <Petrosianic>, to have dealt with this privately would have been a better way of going about things.

<Howard: Keep in mind that Petrosian and Korchnoi were already bitter enemies at the time this match was played....>

Any idea when the breach came? I do not recall reading evidence of any negativity in their relationship prior to this match.