Viktor Korchnoi

Viktor Lvovich Korchnoi was a Soviet and later Swiss chess grandmaster and writer, born in Leningrad in 1931 and dead in 2016. He is considered one of the strongest players never to have become World Chess Champion. He defected to the Netherlands in 1976, lived in Switzerland from 1978 and became a Swiss citizen in 1980. He lost the 1974 Candidates final to Anatoly Karpov, then won the Candidates again in the next two cycles and lost the World Championship matches to Karpov in 1978 and 1981. Korchnoi was a Candidate on ten occasions, four times USSR champion, and at the age of 75 he won the 2006 World Senior Chess Championship, becoming the oldest player ever ranked among the top one hundred.