Korchnoi

Viktor Korchnoi was born in Leningrad in 1931 and became one of the most persistent rivals within the Soviet elite. He won four Soviet championships and appeared in the Candidates stage ten times. The Candidates process selects the challenger for the world title.

In 1974 he lost the Candidates final to Anatoly Karpov by one point. That contest was not yet a title match; it decided who would challenge Bobby Fischer. After leaving the Soviet Union in 1976, Korchnoi won two consecutive cycles and did face Karpov for the World Chess Championship in 1978 and 1981. He lost both contests, although the first was extremely close.

His play was marked by resistance and counterattack. To counterattack is to answer an opponent's pressure and threats by creating threats of your own rather than only defending. Korchnoi found resources in difficult positions and continued posing hard decisions even when his position was worse. He remained world-class for decades and kept competing long after nearly all of his contemporaries had retired.