Before Petrosian no one had studied this.

Another disappointment for Spassky came at the qualifier for the next Interzonal, the Soviet final, played in Moscow 1961, where he again lost a crucial last-round game, this to Leonid Stein, who thus qualified, as Spassky finished equal fifth with 11 / 19, while Petrosian won.

Spassky lost a keenly fought match to Petrosian in Moscow, with three wins against Petrosian's four, with seventeen draws, though the last of his three victories came only in the twenty-third game, after Petrosian had ensured his retention of the title, the first outright match victory for a reigning champion since the latter of Alekhine's successful defences against Bogoljubov in 1934.

Petrosian was a Candidate for the World Championship on eight occasions ( 1953, 1956, 1959, 1962, 1971, 1974, 1977 and 1980 ).

Petrosian earned the title of Master during the 1947 USSR Chess Championship, though he failed to qualify for the finals.

It was in this tournament that Petrosian faced world champion Botvinnik for the first time.

I deliberately exclude Petrosian from the group, since from the very first rounds the latter has made it clear that he is playing for an easier, but also honourable conquest — a place in the interzonal quartet.

After playing in the 1962 Interzonal in Stockholm, Petrosian qualified for the Candidates Tournament in Curaçao along with Pal Benko, Miroslav Filip, Bobby Fischer, Yefim Geller, Paul Keres, Viktor Korchnoi, and Mikhail Tal.

As evidence for this claim, he noted that all 12 games played between Petrosian, Geller, and Keres were draws.

Having won the Candidates Tournament, Petrosian earned the right to challenge Mikhail Botvinnik for the title of World Chess Champion in a 24-game match.

In addition to practicing his chess, Petrosian also prepared for the match by skiing for several hours each day.

Upon becoming World Champion, Petrosian campaigned for the publication of a chess newspaper for the entire Soviet Union rather than just Moscow.

Petrosian was not selected for the Soviet Olympiad side until 1958 ; he had already been a Candidate twice by that time.

Petrosian also made the Soviet team for the first eight European Team Championships ( from 1957 to 1983 ).

Petrosian was known for his use of the " positional exchange sacrifice ", where one side sacrifices a rook for the opponent's bishop or knight.

Petrosian introduced the exchange sacrifice for the sake of ' quality of position ', where the time factor, which is so important in the play of Alekhine and Tal, plays hardly any role.

He tied for third place in the 1961 Soviet Championship, at Moscow, defeating Tigran Petrosian on the way.

At Zürich 1961, he tied for 6th – 7th places with 6 / 11, as Keres won ahead of Tigran Petrosian.

* 7. d5 is the Petrosian System, so named for the 1963-69 world champion, who often essayed the line in the 1960s, with Vladimir Kramnik playing this variation extensively in the 1990s.

In 1977 Viktor Korchnoi and former World Champion Tigran Petrosian played a twelve-game quarter-final Candidates Match to ultimately determine the challenger for the 1978 World Championship.

By 1946, Petrosian had earned the title of Candidate Master.

Petrosian was awarded the title of Master of Sport of the USSR in 1960, and won a second Soviet title in 1961.

Today the Petrosian Variation is still considered the most pressing variation, with the greatest score in Master games.

In employing this system against Petrosian, Spassky was likely inspired by the Slovak International Master Maximilian Ujtelky, who had been experimenting with similar openings for several years.

He shared second place in the 26th Soviet final with Tal, at Tbilisi 1959, finishing a point behind champion Tigran Petrosian, on 12½ / 19.

Spassky then finished ahead of Petrosian and a super-class field at Santa Monica 1966 ( the Piatigorsky Cup ), with 11½ / 18, half a point ahead of Bobby Fischer, as he overcame the American grandmaster's challenge after Fischer had scored 3½ / 9 in the first cycle of the event.

The final was against his Leningrad rival Korchnoi at Kiev, and Spassky triumphed (+ 4 − 1 = 5 ), which earned him another match with Petrosian.

Spassky finished in fourth place at the annual IBM tournament held in Amsterdam, one point behind winners Petrosian and Albin Planinc.

* Boris Spassky vs Tigran Petrosian, World Championship match, Moscow 1969, game 19, Sicilian Defence, Najdorf Variation ( B94 ), 1 – 0 Aggressive style of play and brilliant sparkles of combinations shows Spassky at his heights.

Petrosian ( standing on right, with jacket ) at the 1961 European Chess Team Championship.

However, Spassky would defeat Efim Geller, Bent Larsen and Viktor Korchnoi in the next candidates cycle earning a rematch with Petrosian, at Moscow 1969.

It was the continuation of a bitter feud between the two, dating back at least to their 1974 Candidates semifinal match in which Petrosian withdrew after five games while trailing 3. 5 – 1. 5 (+ 3 − 1 = 1 ).

In 1953, he won a training tournament in Gagra and finished third at Bucharest, behind Tolush and Petrosian.

There followed a second place at The Alexander Memorial ( Teesside ) in 1975 ( after Geller ), a first place at Szolnok ( also 1975 ), and a multi-way share of second at the large Lone Pine Open of 1976 ( Petrosian won ).

The same year, he finished second at Bar, after Petrosian and second at Baguio City, after Torre.

He then won at Tbilisi 1946 ( hors concours in the Georgian Championship ) with a near-perfect score of 18 / 19, ahead of Vladas Mikėnas and a 16-year-old Tigran Petrosian.

At Curaçao in 1962 there was an unofficial conspiracy by Petrosian, Geller and Keres, and this worked out to Keres ' disadvantage, since he may have been slightly stronger than both Petrosian and Geller at this stage.

Then in 1951, he triumphed again at Moscow, URS-ch19, with 12 / 17 (+ 9 = 6 − 2 ), against a super-class field which included Efim Geller, Petrosian, Smyslov, Botvinnik, Yuri Averbakh, David Bronstein, Mark Taimanov, Lev Aronin, Salo Flohr, Igor Bondarevsky, and Alexander Kotov.

He was the champion at Zürich 1961 ( 9 / 11, ahead of Petrosian ).

Keres shared first with World Champion Tigran Petrosian at the very strong 1963 Piatigorsky Cup in Los Angeles with 8. 5 / 14.

He shared first place with World Champion Tigran Petrosian at Buenos Aires 1964, with 12. 5 / 17.

He placed 5th at San Antonio 1972 on 9. 5 / 15, as Petrosian, Lajos Portisch, and Anatoly Karpov won.