1 Early life and background
1.1 Family and childhood
Viktor Lvovich Korchnoi was born on 23 March 1931 in Leningrad (now Saint Petersburg), Soviet Union. His father, Lev Merkuryevich Korchnoi, was a lawyer of Polish-Jewish descent, and his mother, Zinaida Aronovna, was a homemaker. The family faced hardship during the Stalinist purges and World War II; his father was arrested in 1937 and spent several years in a labor camp, while the family endured the Siege of Leningrad. Viktor survived the siege with his mother and sister, an experience that instilled a lifelong resilience.
1.2 Introduction to chess
Korchnoi learned chess at age five from his father, who was an amateur player. He quickly showed aptitude, joining the Leningrad Palace of Pioneers chess circle. His early coaches included the prominent master Vladimir Zak. By age 14, he had earned the Candidate Master title and began competing in adult tournaments.
1.3 Early tournament successes
Korchnoi's first major success came in 1947 when he won the Leningrad Junior Championship. In 1951, he shared first place in the Soviet Junior Championship. He earned the title of International Master in 1954, and Grandmaster in 1956 after strong showings at the Hastings and Moscow international tournaments.
2 Chess career
2.1 Soviet period (to 1976)
2.1.1 Soviet Championship titles
Korchnoi won the Soviet Championship four times, establishing himself as one of the country's elite players.
2.1.1.1 1960, 1962, 1964, 1970
- 1960: Shared first place with Tigran Petrosian in Leningrad.
- 1962: Won outright in Yerevan, scoring 14/19.
- 1964: Won outright in Kiev with 13/19.
- 1970: Won outright in Riga, scoring 12/17.
2.1.2 World Championship Candidate matches
Korchnoi reached the Candidates Tournament multiple times, coming close to challenging for the world title.
2.1.2.1 First Candidates cycle (1968)
In the 1968 Interzonal, Korchnoi qualified for the Candidates matches. He defeated Samuel Reshevsky in the quarterfinals (+3 -2 =5) but lost to Mikhail Tal in the semifinals (+1 -2 =7). This marked his first deep run in the championship cycle.
2.1.2.2 Second Candidates cycle (1974)
Korchnoi again qualified via the 1973 Interzonal. He won his quarterfinal match against Henrique Mecking (+3 -1 =5) and his semifinal against Tigran Petrosian (+3 -1 =1, with five draws). In the final he faced Anatoly Karpov, losing by a narrow margin (+1 -3 =5). The match was marred by controversial incidents, including disputes over adjournments and Karpov's defaulted game due to illness. Karpov went on to become world champion after Bobby Fischer forfeited his title.
2.2 Defection and international career
2.2.1 Defection to the West (1976)
In July 1976, while participating in a tournament in Amsterdam, Korchnoi sought political asylum in the Netherlands. He had grown disillusioned with the Soviet authorities' constant surveillance, restrictions on travel, and pressure to throw games. After a brief stay, he settled in Switzerland, where he received citizenship and became a Swiss chess federation representative.
2.2.2 World Championship matches vs. Karpov
Korchnoi qualified as the official challenger for the world championship twice, both times facing Anatoly Karpov.
2.2.2.1 1978 match in Baguio
The match was held in Baguio, Philippines, from July to October 1978. Karpov led 5–2 after 27 games, but Korchnoi mounted a comeback, winning three consecutive games to tie at 5–5. Karpov eventually won by a score of 6–5 (with 21 draws). The match was noted for its psychological warfare, including Karpov's use of Dr. Vladimir Zukhar (a hypnotist) and Korchnoi's reflective sunglasses.
2.2.2.2 1981 match in Merano
The rematch took place in Merano, Italy, in 1981. Karpov dominated, winning six games to two (with ten draws) to retain the title. Korchnoi struggled with the match conditions and Karpov's superior preparation, but he remained competitive throughout.
2.2.3 Other major tournament victories
After defecting, Korchnoi won many top international events, including the 1977 Horgen tournament, 1979 Wijk aan Zee (shared), 1980 Amsterdam (shared), 1985 Lugano, and 1986 Solingen. He also won the Swiss Championship in 1982 (shared) and 1985.
2.3 Later career (1980s–2000s)
2.3.1 Continued top-level play
2.3.1.1 Senior chess achievements
Korchnoi remained active in top tournaments into his 60s. He won the World Senior Chess Championship in 2006 at age 75, and again in 2007, becoming the oldest winner of that event. He also won numerous other senior tournaments.
2.3.1.2 Record longevity
Korchnoi held a remarkable span at the elite level. He played in the Candidates Tournament for the world championship as late as 1991 (age 60) and remained in the world top 100 until his early 70s. His last classical tournament was the 2015 European Club Cup. He was one of the few players to have competed in six different decades (1940s through 2000s).
3 Playing style and legacy
3.1 Defensive and counterattacking technique
Korchnoi was renowned for his tenacious defensive play and resourceful counterattacks. He excelled in complex, tactical positions where he could exploit opponent overextensions. His ability to find hidden resources under pressure earned him the nickname "Viktor the Terrible" among admirers.
3.2 Opening preferences
In his early career, Korchnoi favored sharp lines such as the King's Indian Defense and the Najdorf Sicilian. Later, he adopted more universal approaches, including the Caro–Kann (as Black) and the English Opening (as White). He was also a noted expert in the Scandinavian Defense, which he used to surprise opponents.
3.3 Impact on chess theory
Korchnoi contributed significantly to opening theory. Lines named after him include the Korchnoi Variation of the Queen's Indian Defense (1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6) and several variations in the Alekhine Defense and the Ruy Lopez. His deep analysis of endgames, particularly rook endings, influenced subsequent generations.
3.4 Reputation and influence
Korchnoi is widely regarded as one of the strongest players never to become world champion. His rivalry with Karpov is considered one of the greatest in chess history. He inspired many with his defiance of Soviet authority and his longevity. Players such as Garry Kasparov and Magnus Carlsen have cited his determination and work ethic as models.
4 Personal life
4.1 Family and relationships
Korchnoi married three times. His first wife was Bella (1950s–1960s), with whom he had a son, Igor. His second marriage to Lily (1970s) ended in divorce. In 1978, he married his long-time companion, Petra (Petra Leeuwerik), a former chess student from the Netherlands. They remained together until his death. Korchnoi also had a daughter, Olga, from a later relationship.
4.2 Life in Switzerland
After defecting, Korchnoi settled in Wohlen, near Zurich. He obtained Swiss citizenship in 1980. He lived modestly, continuing to play chess and write. He became a Swiss chess coach and was active in the Swiss Chess Federation. He often expressed gratitude for the freedom and opportunities in his adopted country.
4.3 Death and posthumous recognition
Korchnoi died on 6 June 2016 in Wohlen at the age of 85. His funeral was attended by many chess figures, including former rivals. In 2017, a memorial tournament was held in his honor in Zurich. The "Viktor Korchnoi Memorial" has since become an annual event. He was posthumously inducted into the World Chess Hall of Fame in 2019.