The 1978 World Chess Championship was played between Anatoly Karpov and Viktor Korchnoi in Baguio, Philippines, from 18 July to 18 October 1978. Karpov won, thereby retaining the title.

The match had many bizarre incidents. Karpov's team included noted Soviet psychologist and hypnotherapist , while Korchnoi enlisted the help of two American Ananda Marga yoga specialists who had recently been convicted of attempted murder and released on bail. There was more controversy off the board, with histrionics ranging from X-raying of chairs, protests about the flags used on the board, and Korchnoi's complaints that Zukhar, sitting in the front row, attempted to hypnotize him. When Karpov's team sent him a blueberry yogurt during a game without any request for one by Karpov, the Korchnoi team protested, claiming it could be some kind of code. They later said this was intended as a parody of earlier protests, but it was taken seriously at the time. It has also been alleged, based on the Mitrokhin Archive, that prior to the match the KGB assembled a team of eighteen foreign intelligence operations officers to try to ensure Korchnoi's defeat.Andrew, Christopher. The Sword and the Shield. p. 560.

In quality of play, the match itself never measured up to the press headlines that it generated, although as a sporting contest it had its share of excitement. The match would go to the first player to win six games, draws not counting. After 17 games, Karpov had a 4–1 lead. Korchnoi won game 21, but Karpov won game 27, putting him on the brink of victory with a 5–2 lead. Korchnoi fought back, scoring three wins and one draw in the next four games to equalize the match at 5–5 after 31 games. Karpov won the very next game, however, and the match, by 6–5 with 21 draws.

1976 Interzonal tournaments

Two interzonal tournaments were held in 1976 in Manila and Biel, with the top 3 from each qualifying for the Candidates Tournament.

{| class="wikitable" |+ June–July 1976 Interzonal, Manila |- ! !! !! Rating !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7 !! 8 !! 9 !! 10 !! 11 !! 12 !! 13 !! 14 !! 15 !! 16 !! 17 !! 18 !! 19 !! 20 !! Total |- style="background:#ccffcc;" | 1 || align=left| || 2620 || – || ½ || ½ || 1 || ½ || ½ || ½ || 1 || ½ || 0 || ½ || 1 || ½ || 1 || 1 || ½ || ½ || 1 || 1 || 1 || 13 |- style="background:#ccffcc;" | 2 || align=left| || 2635 || ½ || – || 0 || ½ || ½ || ½ || ½ || ½ || 1 || ½ || 1 || ½ || ½ || 1 || ½ || 1 || 1 || ½ || 1 || 1 || 12½ |- style="background:#ccffcc;" | 3 || align=left| || 2600 || ½ || 1 || – || 0 || ½ || 0 || ½ || 0 || ½ || ½ || 1 || ½ || 1 || ½ || 1 || 1 || 1 || 1 || 1 || 1 || 12½ |- | 4 || align=left| || 2550 || 0 || ½ || 1 || – || ½ || ½ || 0 || 1 || ½ || ½ || ½ || ½ || 0 || 1 || 1 || 1 || 1 || ½ || 1 || 1 || 12 |- | 5 || align=left| || 2475 || ½ || ½ || ½ || ½ || – || 1 || 1 || 1 || ½ || 0 || ½ || 0 || 1 || 1 || ½ || 0 || ½ || ½ || 1 || 1 || 11½ |- | 6 || align=left| || 2620 || ½ || ½ || 1 || ½ || 0 || – || 0 || 0 || 1 || ½ || 0 || ½ || 1 || 1 || 1 || 1 || ½ || 1 || ½ || 1 || 11½ |- | 7 || align=left| || 2540 || ½ || ½ || ½ || 1 || 0 || 1 || – || ½ || ½ || 1 || ½ || 1 || 0 || ½ || 0 || 0 || ½ || ½ || 1 || 1 || 10½ |- | 8 || align=left| || 2520 || 0 || ½ || 1 || 0 || 0 || 1 || ½ || – || 1 || 1 || 0 || ½ || ½ || 0 || ½ || ½ || 1 || 1 || ½ || 1 || 10½ |- | 9 || align=left| || 2545 || ½ || 0 || ½ || ½ || ½ || 0 || ½ || 0 || – || 1 || ½ || ½ || ½ || 1 || ½ || ½ || 1 || 1 || 1 || ½ || 10½ |- | 10 || align=left| || 2630 || 1 || ½ || ½ || ½ || 1 || ½ || 0 || 0 || 0 || – || ½ || 1 || ½ || ½ || ½ || ½ || ½ || ½ || ½ || 1 || 10 |- | 11 || align=left| || 2540 || ½ || 0 || 0 || ½ || ½ || 1 || ½ || 1 || ½ || ½ || – || 1 || ½ || ½ || ½ || ½ || 0 || ½ || 1 || ½ || 10 |- | 12 || align=left| || 2555 || 0 || ½ || ½ || ½ || 1 || ½ || 0 || ½ || ½ || 0 || 0 || – || 1 || 1 || ½ || 1 || 1 || ½ || 0 || 1 || 10 |- | 13 || align=left| || 2470 || ½ || ½ || 0 || 1 || 0 || 0 || 1 || ½ || ½ || ½ || ½ || 0 || – || 1 || ½ || ½ || 1 || 1 || 1 || 0 || 10 |- | 14 || align=left| || 2540 || 0 || 0 || ½ || 0 || 0 || 0 || ½ || 1 || 0 || ½ || ½ || 0 || 0 || – || 1 || 1 || 1 || 1 || 1 || 1 || 9 |- | 15 || align=left| || 2585 || 0 || ½ || 0 || 0 || ½ || 0 || 1 || ½ || ½ || ½ || ½ || ½ || ½ || 0 || – || 1 || 1 || ½ || 0 || 1 || 8½ |- | 16 || align=left| || 2505 || ½ || 0 || 0 || 0 || 1 || 0 || 1 || ½ || ½ || ½ || ½ || 0 || ½ || 0 || 0 || – || 0 || 1 || 1 || 0 || 7 |- | 17 || align=left| || 2460 || ½ || 0 || 0 || 0 || ½ || ½ || ½ || 0 || 0 || ½ || 1 || 0 || 0 || 0 || 0 || 1 || – || 1 || ½ || 0 || 6 |- | 18 || align=left| || 2520 || 0 || ½ || 0 || ½ || ½ || 0 || ½ || 0 || 0 || ½ || ½ || ½ || 0 || 0 || ½ || 0 || 0 || – || ½ || ½ || 5 |- | 19 || align=left| || 2365 || 0 || 0 || 0 || 0 || 0 || ½ || 0 || ½ || 0 || ½ || 0 || 1 || 0 || 0 || 1 || 0 || ½ || ½ || – || ½ || 5 |- | 20 || align=left| || 2380 || 0 || 0 || 0 || 0 || 0 || 0 || 0 || 0 || ½ || 0 || ½ || 0 || 1 || 0 || 0 || 1 || 1 || ½ || ½ || – || 5

Mecking, Polugaevsky, and Hort qualified for the Candidates Tournament.

{| class="wikitable" |+ July–August 1976 Interzonal, Biel |- ! !! !! Rating !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7 !! 8 !! 9 !! 10 !! 11 !! 12 !! 13 !! 14 !! 15 !! 16 !! 17 !! 18 !! 19 !! 20 !! Total |- style="background:#ccffcc;" | 1 || align=left| || 2625 || – || 0 || 1 || ½ || ½ || 0 || ½ || ½ || ½ || ½ || 1 || ½ || 1 || ½ || ½ || 1 || 1 || 1 || 1 || 1 || 12½ |- style="background:#ccffcc;" | 2 || align=left| || 2635 || 1 || – || ½ || ½ || ½ || ½ || 1 || ½ || ½ || ½ || ½ || 1 || ½ || ½ || ½ || 1 || ½ || 0 || 1 || 1 || 12 |- style="background:#ccffcc;" | 3 || align=left| || 2625 || 0 || ½ || – || 0 || ½ || ½ || ½ || 1 || 1 || 1 || 1 || 1 || ½ || 1 || 1 || 0 || ½ || 1 || 0 || 1 || 12 |- | 4 || align=left| || 2615 || ½ || ½ || 1 || – || 0 || 1 || 1 || ½ || ½ || ½ || ½ || ½ || ½ || ½ || ½ || ½ || ½ || 1 || 1 || 1 || 12 |- | 5 || align=left| || 2580 || ½ || ½ || ½ || 1 || – || 0 || ½ || 1 || ½ || ½ || ½ || ½ || ½ || 1 || ½ || ½ || 1 || 1 || ½ || ½ || 11½ |- | 6 || align=left| || 2540 || 1 || ½ || ½ || 0 || 1 || – || ½ || ½ || 0 || ½ || ½ || ½ || 1 || ½ || ½ || ½ || 1 || 1 || ½ || 1 || 11½ |- | 7 || align=left| || 2585 || ½ || 0 || ½ || 0 || ½ || ½ || – || ½ || 1 || ½ || ½ || ½ || 1 || 1 || ½ || ½ || 1 || ½ || 1 || 1 || 11½ |- | 8 || align=left| || 2585 || ½ || ½ || 0 || ½ || 0 || ½ || ½ || – || 0 || ½ || 0 || ½ || ½ || ½ || 1 || 1 || 1 || 1 || 1 || 1 || 10½ |- | 9 || align=left| || 2490 || ½ || ½ || 0 || ½ || ½ || 1 || 0 || 1 || – || ½ || 0 || 0 || 0 || 1 || 1 || 1 || 0 || 1 || 1 || ½ || 10 |- | 10 || align=left| || 2620 || ½ || ½ || 0 || ½ || ½ || ½ || ½ || ½ || ½ || – || ½ || 1 || ½ || ½ || 0 || ½ || 1 || 0 || 1 || 1 || 10 |- | 11 || align=left| || 2615 || 0 || ½ || 0 || ½ || ½ || ½ || ½ || 1 || 1 || ½ || – || 0 || ½ || 1 || 1 || ½ || ½ || 1 || ½ || 1 || 10 |- | 12 || align=left| || 2505 || ½ || 0 || 0 || ½ || ½ || ½ || ½ || ½ || 1 || 0 || 1 || – || ½ || ½ || ½ || ½ || ½ || ½ || ½ || 1 || 9½ |- | 13 || align=left| || 2540 || 0 || ½ || ½ || ½ || ½ || 0 || 0 || ½ || 1 || ½ || ½ || ½ || – || 0 || ½ || 1 || ½ || ½ || 1 || ½ || 9 |- | 14 || align=left| || 2480 || ½ || ½ || 0 || ½ || 0 || ½ || 0 || ½ || 0 || ½ || 1 || ½ || 1 || – || ½ || 0 || ½ || 1 || 1 || ½ || 9 |- | 15 || align=left| || 2530 || ½ || ½ || 0 || ½ || ½ || ½ || ½ || 0 || 0 || 1 || 0 || ½ || ½ || ½ || – || ½ || 0 || 1 || 1 || 1 || 9 |- | 16 || align=left| || 2480 || 0 || 0 || 1 || ½ || ½ || ½ || ½ || 0 || 0 || ½ || ½ || ½ || 0 || 1 || ½ || – || ½ || ½ || ½ || 1 || 8½ |- | 17 || align=left| || 2525 || 0 || ½ || ½ || ½ || 0 || 0 || 0 || 0 || 1 || 0 || ½ || ½ || ½ || ½ || 1 || ½ || – || ½ || ½ || 1 || 8 |- | 18 || align=left| || 2380 || 0 || 1 || 0 || 0 || 0 || 0 || ½ || 0 || 0 || 1 || 0 || ½ || ½ || 0 || 0 || ½ || ½ || – || 1 || ½ || 6 |- | 19 || align=left| || 2420 || 0 || 0 || 1 || 0 || ½ || ½ || 0 || 0 || 0 || 0 || ½ || ½ || 0 || 0 || 0 || ½ || ½ || 0 || – || 1 || 5 |- | 20 || align=left| || 2385 || 0 || 0 || 0 || 0 || ½ || 0 || 0 || 0 || ½ || 0 || 0 || 0 || ½ || ½ || 0 || 0 || 0 || ½ || 0 || – || 2½

Larsen qualified outright for the Candidates Tournament. Petrosian, Portisch, and Tal contested a playoff in Varese later in the year for the remaining two spots, from which Petrosian and Portisch qualified.

{| class="wikitable" |+ 1976 playoff, Varese |- ! !! !! Rating !! 1 !! 2 !! 3 !! Total |- style="background:#ccffcc;" | 1 || align=left| || 2635 || align=center|- || 1=== || ==== || 4½ |- style="background:#ccffcc;" | 2 || align=left| || 2625 || 0=== || align=center|- || =1== || 4 |- | 3 || align=left| || 2615 || ==== || =0== || align=center|- || 3½

1977 Candidates tournament

As loser of the last championship (by forfeiture) and runner-up of the previous Candidates tournament, respectively, Bobby Fischer and Korchnoi were seeded directly into the tournament. When Fischer declined, Spassky, as losing semifinalist of the previous tournament, was offered the spot. The two seeded players were joined by the top three from each of the two interzonals. Viktor Korchnoi, formerly a representative of the USSR, was stateless at the time and played under the FIDE flag during this cycle.

Korchnoi narrowly defeated Petrosian again in the Candidates quarterfinals, then comfortably won his matches against Polugaevsky and Spassky to emerge as the official challenger to Karpov.

1978 Championship match

The first player to win six games would be Champion.

+World Chess Championship Match 1978 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Wins Total = = = = = = = 1 = = 0 = 1 1 = = 1 = = = 0 = = = = = 1 0 0 = 0 1 6 16½ = = = = = = = 0 = = 1 = 0 0 = = 0 = = = 1 = = = = = 0 1 1 = 1 0 5 15½

Karpov won, retaining his title.

Games

Game 1: Korchnoi–Karpov, ½–½ . The match began with the Queen's Gambit Declined which became a quiet draw in 18 moves.: tied with 1draw.

Karpov often played the Queen's Indian Defense (3...b6), but in this game chose the Tartakower Defense (called the Makogonov–Bondarevsky in Russian), with 3...d5 and later 7...b6. The Tartakover had featured in two important victories by White in recent world championship play, the game 6 win by Fischer against Spassky in the 1972 World Championship match, and a win by Korchnoi also against Spassky in the 1977 Candidates tournament final match in Belgrade that made Korchnoi the challenger.;

In game 7 of the Candidates final match against Spassky (), Korchnoi played 9.Bxf6 Bxf6 10.cxd5 exd5 11.b4!? and went on to win. Karpov would have prepared for this so Korchnoi tried 9.Bd3 instead, but obtained no advantage and the game was drawn on Karpov's proposal after ().

Game 2: Karpov–Korchnoi, ½–½ . Karpov obtained the small advantage of a bishop versus a knight, but the endgame was drawn in 29 moves.: tied with 2draws.

The Open Defense of the Ruy Lopez was a small surprise. Most observers expected Korchnoi to play the French Defense which he had employed successfully against Spassky in the 1977 Candidates finals match and also against Karpov in 1974, but Korchnoi had many defenses to 1.e4 in his repertoire including the French, the Sicilian, the Alekhine, the Pirc, and the Ruy Lopez.

Karpov was very familiar with the position after 14.Re1 () as he had had it as White in draws against Smyslov at Leningrad 1977 and Tilburg 1977, and in a loss on time to Beliavsky at Leningrad 1977, although Karpov thought he had obtained the opening advantage. In those games Black played the standard move 14...Re8, which was also chosen by Larsen in a win over Fischer at Santa Monica 1966.; , ;

Korchnoi introduced the new move, 14...d4!?. A few moves later after 18...Qd5!, Karpov decided to simplify to an equal endgame and his small advantage of a proved insufficient to win.

Game 3: Korchnoi–Karpov, ½–½