Viktor Lvovich Korchnoi born March 23, 1931) is a professional chess player, author and currently the oldest active grandmaster on the tournament circuit. He was born in Leningrad, USSR, defected to the Netherlands in 1976, and has been residing in Switzerland for many years.
Korchnoi played three matches against Anatoly Karpov, the latter two for the World Chess Championship. In 1974, he lost the Candidates final to Karpov, who was declared world champion in 1975 when Bobby Fischer failed to defend his title. Then he won consecutive Candidates cycles to qualify for World Championship matches with Karpov in 1978 and 1981, losing both.
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. In September 2006, he won the World Senior Chess Championship. (For more info, read the Wikipedia article.)
GAME SOURCE: Modern Chess Miniatures©1960 by IM Barden and Wolfgang Heidenfeld, p. 92. Unattributed analysis/comments are by IM Barden.