Magnus Carlsen leaves Sinquefield Cup amid Niemann chess ‘cheating’ furore

The chess world is in turmoil after the world champion, Magnus Carlsen, pulled out of a major tournament for the first time in his career with frenzied speculation over whether an opponent cheated.

On Monday, organisers of the $500,000 (£433,000) Sinquefield Cup announced additional anti-cheating precautions, including a 15-minute delay in the broadcast of the moves and increased radio-frequency identification checks. But Carlsen had already withdrawn from the event, announcing it in a tweet with a video of José Mourinho saying: “If I speak I am in big trouble. Big, big trouble.”

Carlsen did not offer any further explanation but the American grandmaster and popular streamer Hikaru Nakamura said Carlsen had pulled out because he suspected his third-round opponent, Hans Niemann, was “probably cheating”.

The 19-year-old Niemann, who has made spectacular progress into the world’s top 50, shocked Carlsen on Sunday by beating him with the black pieces. Niemann said that “by some ridiculous miracle” he had guessed what his opponent’s obscure opening would be and prepared deeply for it that morning. “Magnus must be embarrassed to lose to me,” he said.

But while many praised Niemann’s victory, others were more sceptical. They included Nakamura, the world’s highest-rated blitz player, who said Carlsen would not quit an event without good reason. “Magnus would never do this in a million years,” he said. “He just doesn’t do that. He’s the ultimate competitor, he’s a world champion.

“He wouldn’t do this unless he really strongly believes Hans is cheating with a very strong conviction. I think he just thinks Hans is just cheating, straight out.”

Nakamura, who is closely affiliated with the world’s biggest chess website,, suggested Niemann had been banned from playing online in the past. “That is not up for debate, that is a known fact,” he said.

That claim appeared to be supported by another American grandmaster, Andrew Tang, who suggested that he had “stopped talking to Hans because of that stuff with”.

However, Daniel Rensch, the chief chess officer of, refused to confirm or deny the allegations. “ does not discuss fair play matters publicly and, as such, we decline to comment on the happenings at Sinquefield Cup and/or any speculations made by the community,” he said.

It is extremely difficult to prove cheating in over-the-board chess and there is no evidence of wrongdoing on Niemann’s part at the event. Another grandmaster at the Sinquefield Cup, Levon Aronian, appeared to give him the benefit of the doubt, saying:“It quite often happens when young players play very well, there are always accusations towards them.

“All of my colleagues are pretty much paranoid and quite often I was the one telling them, come on guys, I know myself, I’m an idiot and I’m a good player.’

Niemann was back at the board on Monday evening, where he drew against the French player Alireza Firouzja. Niemann was asked about Carlsen’s withdrawal, but not about the cheating allegations. He expressed shock at what had happened. “I was struggling to even focus, I was thinking about it the entire game,” he said.

“It’s very weird. I don’t want to draw any conclusions, but it’s very strange. At least I got to beat him before he left – that’s the good thing.”

The Guardian has emailed Niemann to ask him whether he has cheated, what his response is to Nakamura’s comments, and whether he has previously been banned from

Another grandmaster, Jacob Aagaard, a coach who has worked with Niemann, has backed the American. “It is reasonably well established that Hans cheated online at some point,” Aagard said. “This is simply a different thing. Compare it to cheating in homework club. There are times when people have cheated on their homework and I ignore it. Because it is not a big thing. It does not make me believe that they will start on advanced Mission Impossible-style careers as advanced cheaters.”

Emil Sutovsky, the director general of Fide, the chess governing body, dismissed suggestions that Carlsen had quit because he was a bad loser. “He must have had a compelling reason, or at least he believes he has it,” Sutovsky wrote on Twitter. “Don’t call him a sore loser or disrespectful. I shall not speculate on the reasons for his withdrawal, but probably would expect a tournament director to air them.”