According to his friend Dr Christian Issler, the President of the Zurich Chess Club, Viktor Korchnoi suffered the stroke a while ago. The Swiss national of Russian origin lives in Wohlen, near Zurich, and is 81 years old. He was playing quite vigorously until September this year. In 2011 he beat the chess star Fabiano Caruana, today number five in the world, at the Tradewise Gibraltar Chess Festival. The game and result made the news because the two players were, remarkably, more than sixty year apart in age. The same year Korchnoi won the Botvinnik Memorial Veterans' rapid chess tournament in Russia (August 2011), scoring 7.0/9 points, one more than his nearest rival in a field that included Mark Taimanov, Lajos Portisch, Wolfgang Uhlmann, Evgeny Vasiukov, Igor Zaitsev, Aleksandar Nikitin, Borislav Ivkov, Oleg Chernikov and Anatoly Bykhovsky.

This year "Viktor the Terrible" played in an event pitting the Geneva Chess Club against famous chess legends (Korchnoi, Ribli, Spraggett, Andersson and Hort). At the time we filed a report with pictures by Frits Agterdenbos of ChessVista. Here an excerpt:

Korchnoi was still playing at the end of September 2012, when he drew against the many times Italian national champion GM Michele Godena in the Swiss league.

Korchnoi giving a simultaneous exhibition in London last year...

The great chess fighter is currently in a clinic, following a stroke and additional complications brought on by heart problems. Friends and family hope that he will be released soon and can return to his home in Wohlen. We wish Viktor Lvovich, whom we have known and cherished as a friend for decades, a speedy recovery, with peace and rest in his twilight years.

Some recent ChessBase articles on Viktor Korchnoi

Viktor is still the Terrible! 19.08.2012 – The trend of matches between aging champions and another set of players is an attractive one, and has been tried in many forms. The Geneva Chess Club proposed its own spin by pitting its aspiring masters against a group of legendary players. The veterans won, led by Viktor Korchnoi, 81 years-old, bound to a wheelchair. Report, video, plus photos by Frits Agterdenbos.

Viktor Korchnoi: My Life for Chess (Part two) 26.06.2012 – Born in 1931, twice contender for the world championship, Viktor Korchnoi is a living chess legend. In his career spanning over 60 years he has crossed swords with practically every great player of the past and present, including Bobby Fischer and Garry Kasparov. In this special Monograph DVD, "Viktor the Terrible" describes a life devoted to chess. Review by Prof. Nagesh Havanur.

Viktor Korchnoi: My Life for Chess (Part one) 20.06.2012 – Born 1931, two-times contender for the world championship, Viktor Korchnoi is a piece of living chess history. In the 60 years of his career he has crossed swords with practically all great players of the past and present, including Bobby Fischer and Garry Kasparov. In this special Monograph DVD "Viktor the Terrible" describes a life devoted to chess. Review by Prof. Nagesh Havanur.

My Life For Chess - Viktor Korchnoi 28.11.2011 – Viktor Korchnoi hardly needs an introduction. This Methusaleh of chess, whose competitive longevity and endless love for the game even have Kasparov in awe, has competed head-to-head with every world champion since Botvinnik. In his review, Albert Silver explains why these two DVDs are his favorite, and how they not only entertain and instruct, but also inspire from sheer passion.

Viktor Korchnoi's 80th birthday clock simul 04.04.2011 – A week ago we celebrated Viktor Korchnoi's 80th birthday in Zurich. There was a gala dinner with chess prominence, but before that the octogenarian gave a handicap clock simul against ten talented members of the Swiss juniors. Viktor Lvovich won the match 8-2 and played some very attractive games. The juniors sent them to us with their notes. Big pictorial report.

Viktor Korchnoi's 80th Birthday Celebration 28.03.2011 – On Saturday the Schachgesellschaft Zürich celebrated the anniversary of someone who had done more for chess in Switzerland than any other player. Viktor Korchnoi, born on March 23 1931, kicked things off with a clock simul and then attended a gala dinner in his honour. Guests included Mark Taimanov and Garry Kasparov. We bring you a big pictorial report by Frederic Friedel.

Viktor Korchnoi turns eighty 23.03.2011 – One of the defining chess players of our time is the indomitable Viktor Korchnoi. Born on March 23 1931, this chess legend is still going strong, taking part in high level tournaments, travelling and playing like a young man. So what do you think he is doing in his birthday week? Relaxing, reading a good book, sipping port? Then you don't know the man. Biography, pictures and videos.

Korchnoi vs Spassky finish 4-4 in Elista 27.12.2009 – The "Battle of the Giants" between tenth World Champion Boris Spassky, 72, and multiple World Championship challenger Viktor Korchnoi, 78 began with the latter pressing. But in the second half of the match it was Spassky who called the shots. He won two games and blundered away a good position in a third. Not bad after almost seven years of "hibernation". Report and games.

Korchnoi vs Spassky in Elista 19.12.2009 – It is billed as the "Battle of the Giants", between tenth World Champion Boris Spassky, 72, and multiple World Championship challenger Viktor Korchnoi, 78. The latter is still very active in competitive play, while Spassky has essentially retired from chess. In the first game an exhausted Korchnoi (he had rushed to Kalmykia from London) put the pressure on Spassky and won. Illustrated report.

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