What is Viktor Korchnoi?
{{Infobox chess player |playername = Viktor Korchnoi |image = Victor Korchnoi.jpg |caption=Korchnoi in 1993 |birthname = |country = [[Soviet Union]],<br>[[Switzerland]] |datebirth = {{Birth date|1931|3|23}} |placebirth = [[Saint Petersburg|Leningrad]], USSR |datedeath = {{Death date and age|2016|6|6|1931|3|23}} |placedeath = [[Wohlen]], [[Switzerland]] |title = [[Grandmaster (chess)|Grandmaster]] 1956 |worldchampion = |womensworldchampion = |rating = 2566 (January 2010) |peakrating = 2695 (January 1979)<ref>{{cite web|url=http://staff.cs.utu.fi/~juhkivij/chess/elo_records_en.shtml |title=Highest FIDE ratings |publisher=Staff.cs.utu.fi |accessdate=2008-11-23}}</ref>}} '''Viktor Korchnoi''' <ref>{{lang-ru|Ви́ктор Льво́вич Корчно́й}}</ref> (23 March 1931 &ndash; 6 June 2016) was a professional [[Grandmaster (chess)|chess grandmaster]]. He was born in [[Saint Petersburg|Leningrad]], [[USSR]] (Saint Petersburg). In 1976 he defected to [[the Netherlands]]. He lived in [[Switzerland]] for many years, and became a Swiss citizen.<ref>Korchnoi, Victor 2005. ''Chess is my life''. Olms. {{ISBN|3-283-00406-4}}.</ref> Towards the end of his life, he was the oldest active grandmaster on the regular tournament circuit. Viktor was at or near the top in chess for half a century. In all, Korchnoi was a candidate for the World Championship on ten occasions (1962, 1968, 1971, 1974, 1977, 1980, 1983, 1985, 1988 and 1991). Korchnoi was also a four-time USSR chess champion, a five-time member of [[Soviet]] teams that won the European championship, and a six-time member of Soviet teams that won the [[Chess Olympiad]]. == Matches against Karpov == Korchnoi played three matches against [[Anatoly Karpov]], the latter two for the [[World Chess Championship]]. In 1974, he lost the [[Candidates Tournament|Candidates]] final to Karpov by the narrowest margin: 11.5–12.5. Karpov was declared world champion in 1975 when [[Bobby Fischer]] failed to defend his title. Then, after defecting from the Soviet Union in 1976, Korchnoi won two Candidat