Bolgoljubov: Notes and comments from Victor Korchnoi about this game:
This was Korchnoi’s final game of the Interzonal Tournament in Leningrad (not to be confused with the Candidates Tournament of 1973). Korchnoi considers it one of his finest tournament performances of his career. He finished in first place, ahead of Karpov, who came in second. Both had scores of 13.5/18 but Korchnoi won in tie break points (108.25 / 104.25). In this tournament Korchnoi lost only one game, against Josip Rukavina.
Korchnoi describes the tournament as a “fist fight with Anatoly Karpov for first place”. Before the final game Korchnoi suggested to Karpov that they make 2 shorts draws because they already secured 1st and 2nd places. However, Karpov’s final round opponent was Eugenio Torre (7/18) who was struggling. Karpov had the opportunity to win the tournament outright if he beat Torre and if Korchnoi either drew or lost to Robert Huebner. So the pressure was on Korchnoi here.
Korchnoi comments that his relationship at this time with Robert Huebner was good. Huebner's reasons for his withdrawal from the 1980 Candidates Match against Viktor Korchnoi remain a mystery to Korchnoi.
4. e4 setting up the classic Maróczy Bind position with white.
8. Be2 There was a time, after Botvinnik won several games as white that the position here is clearly better for white and black can do nothing against this strong pawn center. Korchnoi does not feel that Botvinnik’s point of view is very logical. He feels black can create plenty of pressure on the white queenside and center.
9… Nc5 = Alexander Kotov, the Chief Arbiter of the Tournament and game annotator declared that black had equalized here. However, Korchnoi feels that his next move 10. b4 refutes that assertion. Had Nc5 been played after both players had castled, things would have been different. Because after Bxc3, Bxc3 the Knight can win the pawn on e4 because the h8 rook is not hanging (via Bxh8).
Korchnoi talks about all of his forward pawn moves in this game. He claims that pawns moved ahead like this are good when you have the initiative but become targets if you lose the initiative. He notes that his position has a hole at d4 because of the advanced pawn moves c4 and e4. Huebner exploits this by posting a knight at d4, but “it is only a single piece”.
16. Re1 with the idea of playing Bf1 next. Play would continue against the black knight at d4 which will have few good squares to retreat to and no pieces to exchange itself for. So Huebner decided to exchange the knight immediately for white's white square bishop.
16… Nxe2+ Korchnoi said that 16… Bxe5 should have occurred before the Nxe5+ so as to fix white’s pawns, but Huebner did not see deeply enough into the position.
18. Rd2 Now the threat is c5. The black queen is vulnerable as is the f7 pawn it is protecting. So Huebner took on d5 with the white square bishop.
18… Bxd5 Now white has a choice:
a] 19. cxd5 gives white the c file.
b] 19. exd5 gives white pressure on the backward e7 pawn.
c] 19. Rxd5 Korchnoi noticed that there were no knights anymore or a white squared white bishop to make his rook vulnerable. He also saw that a rook on d5 would be helpful against the potential black pawn breaks, a5, b5, f5, etc. Offensively the rook helps white with moves like c5 and e5. Korchnoi said, “by the way it (Rxd5) had never been played in grandmaster’s practice”. It was a novelty.
23. g4 Played in order to stop f5. As long as white has the initiative g4 is correct, if white loses the initiative g4 will be a “horrible weakening of the kingside”.
23… Qf6 Korchnoi said, “this is an interesting move”. The black queen is now threatening to penetrate the white camp and hinder the communication and cooperation of the white pieces.
26… Rfc8 To exploit a pin on the c file. This turns out to be a mistake. Correct was the defusing move 26… dxc5.
27… Bf8 For many decades after the game Korchnoi consider this move by Huebner to be “a great mistake”. However, now he realizes that Huebner was correct and that Huebner’s understanding of the position was better than his own. Korchnoi thought that 27…h6 was the correct move. However, after 28.Rc2! Qb1 29. Bxe7! Rxe7 30. cxd6 Ree8 31. d7 black is lost.
29… Rxc7 Now the initiative can shift to either black or white. Korchnoi notes that the black queen is on the white queenside when it really needs to be on the black kingside. Plans should be made to cut it off from the black king.
30. e5! Keeps the initiative for white and cuts the queen off from the black king. If 30…Rc3 31. Qd4 dxe5 32. Qxe5 Rc2 33. Qxb2 Rxb2 34. Bf6! Re2 35. Rd8 Re6 36. g5 with a very unpleasant pin for black.
31. Bd2! A very important move. To arrange the coordination of all pieces and protect the white king.
32. Rd8 threatening Qd6! 32…hg7 is the only move.
33. Qe3 threatening Qh6!
38… Kc4 loses the rook. 39. Qc5+ Kb3 40. Qe3+
Source: “My Life for Chess” by Victor Korchnoi – Chessbase DVD Lecture Series 2005