Former chess world champion Anatoly Karpov makes a move during the first game of the last day of his 25th anniversary match against Garry Kasparov in Valencia September 24, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Anatoly Karpov (L) observes his opponent Garry Kasparov at the start of their 25th anniversary match in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Garry Kasparov looks at the board at the start of his 25th anniversary match against Anatoly Karpov (not pictured) in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Garry Kasparov makes a move against his opponent Anatoly Karpov at the start of their 25th anniversary match in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Anatoly Karpov (L) observes his opponent Garry Kasparov at the start of their 25th anniversary match in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Anatoly Karpov (L) and Garry Kasparov shake hands at the start of their 25th anniversary match in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Anatoly Karpov (L) makes a move against his opponent Garry Kasparov at the start of their 25th anniversary match in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Garry Kasparov looks at the board at the start of his 25th anniversary match against Anatoly Karpov (not pictured) in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Garry Kasparov (R) makes a move against his opponent Anatoly Karpov at the start of their 25th anniversary match in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess World Champions Anatoly Karpov (L) and Garry Kasparov play at the start of their 25th anniversary match in Valencia, September 22, 2009. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess world champion Garry Kasparov smiles at a news conference in Valencia, September 21, 2009, before his 25th anniversary match with Anatoly Karpov to be held Tuesday to Thursday. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess world champion Anatoly Karpov (L) looks at his opponent Garry Kasparov (R) during a news conference in Valencia, September 21, 2009, before their 25th anniversary match to be held from Tuesday to Thursday. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess world champion Garry Kasparov smiles at a news conference in Valencia, September 21, 2009, before his 25th anniversary match with Anatoly Karpov to be held Tuesday to Thursday. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess world champions Garry Kasparov (R) and Anatoly Karpov pose with their chess figures at a news conference in Valencia, September 21, 2009, before their 25th anniversary match to be held Tuesday to Thursday. REUTERS/Heino Kalis (SPAIN SPORT CHESS IMAGES OF THE DAY) 

Former chess world champions Garry Kasparov (L) and Anatoly Karpov shake hands at a news conference in Valencia, September 21, 2009, before their 25th anniversary match to be held Tuesday to Thursday. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former chess world champion Anatoly Karpov listens during a news conference in Valencia, September 21, 2009, before his 25th anniversary match against Garry Kasparov to be held Tuesday to Thursday. REUTERS/Heino Kalis (SPAIN SPORT CHESS) 

Former world chess champion and opposition leader Garry Kasparov speaks during his interview with Reuters in Moscow July 3, 2009. REUTERS/Denis Sinyakov (RUSSIA POLITICS) 

Former world chess champion and opposition leader Garry Kasparov speaks during his interview with Reuters in Moscow July 3, 2009. REUTERS/Denis Sinyakov (RUSSIA POLITICS) 

Opposition leader Garry Kasparov (L) speaks at a rally by the Solidarity opposition movement during International Workers' Day, or Labour Day, celebrations in Moscow May 1, 2009. REUTERS/Thomas Peter (RUSSIA CONFLICT POLITICS) 

Opposition leaders Garry Kasparov (L) and Mikhail Kasyanov stand during the opposition movement Solidarnost protest rally in central Moscow, February 21, 2009. The new opposition movement gathered for its first protest rally to express their dissatisfaction with the present government and its policy. REUTERS/Sergei Karpukhin (RUSSIA) 

Opposition leaders Boris Nemtsov (L) and Garry Kasparov applaud during the inauguration congress of the anti-Kremlin "Solidarity" movement in Moscow December 13, 2008. REUTERS/Denis Sinyakov (RUSSIA) 

Opposition leaders Boris Nemtsov (L) and Garry Kasparov vote during the inauguration congress of the anti-Kremlin "Solidarity" movement in Moscow December 13, 2008. REUTERS/Denis Sinyakov (RUSSIA) 

Opposition leader Garry Kasparov speaks as he gives an interview to Reuters at his apartment in Moscow, November 18, 2008. REUTERS/Denis Sinyakov (RUSSIA) 

Opposition leader Garry Kasparov speaks as he gives an interview to Reuters at his apartment in Moscow, November 18, 2008. REUTERS/Denis Sinyakov (RUSSIA) 

Opposition leader Garry Kasparov speaks as he gives an interview to Reuters at his apartment in Moscow, November 18, 2008. REUTERS/Denis Sinyakov (RUSSIA) 

Opposition leader Garry Kasparov speaks as he gives an interview to Reuters at his apartment in Moscow, November 18, 2008. REUTERS/Denis Sinyakov (RUSSIA) 

U.S. President George W. Bush (L) meets Leader of the Other Russia Coalition Garry Kasparov and other dissidents on Governors Island in New York September 23, 2008. REUTERS/Jim Young (UNITED STATES) 

Opposition leader Garry Kasparov speaks to people during a demonstration in support of Maxim Reznik, head of the Yabloko opposition party in St Petersburg, March 23, 2008. Reznik still faces trial on charges of assaulting a policeman but the court reversed a previous decision to jail him for two months pending trial. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leader Garry Kasparov speaks to people during a demonstration in support of Maxim Reznik, head of the Yabloko opposition party in St Petersburg, March 23, 2008. Reznik still faces trial on charges of assaulting a policeman but the court reversed a previous decision to jail him for two months pending trial. REUTERS/Alexander Demianchuk (RUSSIA) 

Leaders of the opposition Garry Kasparov and Eduard Limonov (R) smile during a news conference in Moscow, March 19, 2008. The harshly anti-Kremlin Other Russia movement called on Russian opposition forces to form a powerful coalition, but some of the invited opposition parties expressed doubts such a grouping would be viable at all. REUTERS/Alexander Natruskin (RUSSIA) 

Opposition supporters march during an authorised rally in central St.Petersburg March 3, 2008. Opposition leader Garry Kasparov, the former world chess champion who attended the rally, said 250 people had been detained in Moscow. The poster in the background reads "For our Freedom". REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition supporters burn flares during an authorised rally in central St.Petersburg March 3, 2008. Opposition leader Garry Kasparov, the former world chess champion who attended the rally, said 250 people had been detained in Moscow. The poster in the background reads "No to Bear!", referring to a widely known nickname of newly elected president Dmitry Medvedev. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leader Garry Kasparov, the former world chess champion, speaks to his supporters during an authorised rally in central St.Petersburg, March 3, 2008. Kasparov said 250 people had been detained during an unauthorised demonstration in Moscow. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leaders Garry Kasparov (R) and Eduard Limonov (L) shout slogans during an authorised rally in central St.Petersburg March 3, 2008. Kasparov said 250 people had been detained during an unauthorised demonstration in Moscow. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leader Garry Kasparov, the former world chess champion, speaks to his supporters during an authorised rally in central St.Petersburg March 3, 2008. Kasparov said 250 people had been detained during an unauthorised demonstration in Moscow. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition supporters burn flares during an authorised rally in central St. Petersburg March 3, 2008. Opposition leader Garry Kasparov, a former world chess champion, attended the rally and said 250 people had been detained in Moscow. REUTERS/Alexander Demianchuk (RUSSIA) 

A protester holds pictures of opposition leader Garry Kasparov in front of special police in central Moscow March 3, 2008. Russian riot police on Monday clashed with protesters who tried to gather in Moscow for an unauthorised rally against the presidential election. REUTERS/Thomas Peter (RUSSIA) 

A protester holds pictures of opposition leader Garry Kasparov in front of special police in central Moscow, March 3, 2008. Russian riot police on Monday clashed with protesters who tried to gather in Moscow for an unauthorised rally against the presidential election. REUTERS/Shamil Zhumatov (RUSSIA) 

A woman stands with a portrait of opposition leader Garry Kasparov in central Moscow as she tries to attend an opposition march, March 3, 2008. Russian riot police on Monday clashed with protesters who tried to gather in Moscow for an unauthorised rally against the presidential election. REUTERS/Konstantin Koutsyllo (RUSSIA) 

Russian opposition leaders Garry Kasparov (R) and Eduard Limonov attend a news briefing in central St.Petersburg March 3, 2008. Russia's next president, Dmitry Medvedev, vows to uphold his mentor Vladimir Putin's policies after winning an election criticised by Western observers as not fully democratic. Russian opposition leaders complained of violations in the conduct of Sunday's presidential election. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leader Garry Kasparov speaks during a news briefing in central St.Petersburg March 3, 2008. Russia's next president, Dmitry Medvedev, vows to uphold his mentor Vladimir Putin's policies after winning an election criticised by Western observers as not fully democratic. Russian opposition leaders complained of violations in the conduct of Sunday's presidential election. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leader Garry Kasparov speaks during a news briefing in central St.Petersburg March 3, 2008. Russia's next president, Dmitry Medvedev, vows to uphold his mentor Vladimir Putin's policies after winning an election criticised by Western observers as not fully democratic. Russian opposition leaders complained of violations in the conduct of Sunday's presidential election. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leader Garry Kasparov speaks during a news briefing in central St.Petersburg March 3, 2008. Russia's next president, Dmitry Medvedev, vows to uphold his mentor Vladimir Putin's policies after winning an election criticised by Western observers as not fully democratic. Russian opposition leaders complained of violations in the conduct of Sunday's presidential election. REUTERS/Alexander Demianchuk (RUSSIA) 

Opposition leader Garry Kasparov stands in front of a poster showing President Vladimir Putin and presidential candidate Dmitry Medvedev near the Kremlin in Moscow March 2, 2008. Russians voted for a new president on Sunday in an election expected to deliver a victory to Kremlin leader Vladimir Putin's chosen successor and another blow to Moscow's already tarnished democratic image. REUTERS/Thomas Peter (RUSSIA) 

Opposition leader Garry Kasparov stands in front of a poster showing President Vladimir Putin and presidential candidate Dmitry Medvedev near the Kremlin in Moscow March 2, 2008. Russians voted for a new president on Sunday in an election expected to deliver a victory to Kremlin leader Vladimir Putin's chosen successor and another blow to Moscow's already tarnished democratic image. REUTERS/Thomas Peter (RUSSIA) 

Opposition leader Garry Kasparov holds a ticket for the Historical Museum as riot police prevent him from entering near the Kremlin in Moscow March 2, 2008. Russians voted for a new president on Sunday in an election expected to deliver a victory to Kremlin leader Vladimir Putin's chosen successor and another blow to Moscow's already tarnished democratic image. REUTERS/Thomas Peter (RUSSIA) 

Opposition leader Garry Kasparov stands in front of the Historical Museum as riot police prevent him from entering near the Kremlin in Moscow March 2, 2008. Russians voted for a new president on Sunday in an election expected to deliver a victory to Kremlin leader Vladimir Putin's chosen successor and another blow to Moscow's already tarnished democratic image. REUTERS/Thomas Peter (RUSSIA) 

Opposition leader Garry Kasparov holds a bag with a slogan denouncing Russia's presidential election as he stands in front of a poster showing President Vladimir Putin and presidential candidate Dmitry Medvedev near the Kremlin in Moscow March 2, 2008. The words read: "I am not taking part in a farce. March 2, 2008." REUTERS/Shamil Zhumatov (RUSSIA) 

Opposition activists Nikita Belykh (2nd L) and Garry Kasparov (C) and editor of an opposition internet magazine Ezhednevny Zhurnal (Daily Magazine) Alexander Ryklin (R) leave the Central Election Commission after delivering a petition describing the election as a "farce" in Moscow March 1, 2008. Less than a day until the world's biggest country elects its new leader, Russian liberals accused the Kremlin of manipulating the vote certain to hand President Vladimir Putin's protege a resounding victory. REUTERS/Denis Sinyakov (RUSSIA) 

Opposition leader Garry Kasparov (L) and Alexander Ryklin, editor-in-chief of opposition internet magazine Ezhednevny Zhurnal (Daily Magazine), arrive at Russia's Central Election Commission to submit a petition in Moscow March 1, 2008. Less than a day until the world's biggest country elects its new leader, Russian liberals accused the Kremlin of manipulating the vote certain to had President Vladimir Putin's protege a resounding victory. The Russian on the folder reads: 'The authorities have turned the election into a farce. I will not take part in this farce.' REUTERS/Denis Sinyakov (RUSSIA) 

Chess grandmaster and opposition leader Garry Kasparov (R) and his wife Dasha Kasparova arrive for the "Cinema for Peace 2008" charity gala supporting UNICEF in Berlin February 11, 2008. The gala was held during the annual Berlinale film festival, which ends on February 17. REUTERS/Fabrizio Bensch (GERMANY) 

Chess grandmaster and opposition leader Garry Kasparov speaks during a news conference on Russia's row with Britain's cultural arm and British Council in Moscow January 18, 2008. Russia claimed victory in its row with the British government's cultural centres on Friday, saying London's decision to close the British Council's regional offices was long overdue. REUTERS/Alexander Natruskin (RUSSIA) 

Former world chess champion and Russian opposition leader Garry Kasparov (C) attends the funeral of 23-year-old activist Yuri Chervochkin in the town of Serpukhov, 100 km (62 miles) south of Moscow, December 13, 2007. A Russian opposition activist accused the authorities of "cynical and immoral" behaviour on Thursday after police briefly held two busloads of activists as they travelled to Chervochkin's funeral. REUTERS/Mikhail Voskresensky (RUSSIA) 

Russian opposition leader Garry Kasparov speaks during a news conference in Moscow December 3, 2007. Russian President Vladimir Putin on Monday defended as legitimate the landslide victory of his party in an election criticised in Europe and denounced by international observers as unfair. REUTERS/Denis Sinyakov (RUSSIA) 

Russian opposition leaders Garry Kasparov (L) and Eduard Limonov attend a news conference in Moscow December 3, 2007. Russian President Vladimir Putin on Monday defended as legitimate the landslide victory of his party in an election criticised in Europe and denounced by international observers as unfair. REUTERS/Denis Sinyakov (RUSSIA) 

Russian opposition leader Garry Kasparov speaks during a news conference in Moscow December 3, 2007. President Vladimir Putin's party won a landslide victory in a parliamentary election, according to official results on Monday, but international observers attacked the vote as "not fair". REUTERS/Denis Sinyakov (RUSSIA) 

Opposition leaders Garry Kasparov (R) and Eduard Limonov arrive in a polling station in Moscow December 2, 2007. Russians voted on Sunday in a parliamentary election wiedely viewed as a referendum on President Vladimir Putin and overshadowed by opposition accusations that pro-Kremlin forces enjoy an unfair advantage. REUTERS/Alexander Natruskin (RUSSIA) 

Opposition leaders Garry Kasparov (L) and Eduard Limonov show their crossed-out ballot papers in a polling station in Moscow December 2, 2007. Russians voted on Sunday in a parliamentary election widely viewed as a referendum on President Vladimir Putin and overshadowed by opposition accusations that pro-Kremlin forces enjoy an unfair advantage. REUTERS/Alexander Reshetnikov (RUSSIA) 

Opposition leader Garry Kasparov leaves a polling station in Moscow December 2, 2007. Russians voted on Sunday in a parliamentary election widely viewed as a referendum on President Vladimir Putin and overshadowed by opposition accusations that pro-Kremlin forces enjoy an unfair advantage. REUTERS/Alexander Natruskin (RUSSIA)