By Frederic Friedel  https://en.chessbase.com/post/viktor-Korchnoi-dies-at-85 Viktor Korchnoi was a professional chess player, one of the strongest grandmasters in the world, twice World Championship challenger, the strongest player never to have won the title. He was also, in recent years, the oldest active grandmaster on the tournament circuit. Viktor Lvovich Korchnoi was born on 23