The world's top-ranked chess player has accused the teenager that beat him of cheating "more – and more recently – than he has publicly admitted."

The controversy stems from a Sept. 4 match in St. Louis between Norwegian world champion Magnus Carlsen, 31, and upstart American Hans Niemann, 19. Niemann's surprise victory ended his opponent's 53-game winning streak, rocking the chess world and sparking accusations of cheating, which Niemann has denied. When the two grandmasters faced off again online on Sept. 20, Carlsen quit after just one move.

Niemann is currently ranked 49th by the International Chess Federation while Carlsen has been the reigning world champion since 2013. There is no evidence Niemann cheated in either game against Carlsen, experts say.

"It is extremely difficult to cheat in over-the-board games and tournaments," Vladimir Drkulec, president of the Chess Federation of Canada, told "There [was] no obvious cheating in the game. Magnus just played badly; like, he played at my level as far as the number of mistakes that he made."

Drkulec, a national master, describes himself as Canada's chess cheating expert. He needs to be: the federation he leads is the game's governing body in Canada.

"Typically, people get caught, so it doesn't pay," Drkulec said. "They're going to be banned from [the International Chess Federation] probably for at least three years, but maybe for life. A top player isn't going to do that, because if he does, he loses his livelihood."

Drkulec's stance is supported by Kenneth Regan, a chess cheating expert and professor of computer science and engineering at the University of Buffalo. Following a computer analysis of the initial controversial match, as well as all of Niemann's games over the past two years, Regan found no reason to suspect the player of cheating against Carlsen.

"There's no concrete basis on which to evaluate his accusation," Regan, who consulted with the St. Louis tournament, told "Neither I nor the tournament staff found any indication of cheating in that game, or in any combination of other games by Niemann at the tournament."


Cheating in online chess is simple – you just need to input moves into a chess program on another device.

"Computers on phones have been king since at least 2010, and this has been a major factor to worry about in tournaments," Regan said. "Deep Blue in 1997 was a supercomputer, but you no longer need so much hardware."

Deep Blue was the towering computer that famously defeated Russian chess grandmaster Garry Kasparov.

Niemann himself has admitted to cheating online when he was 12 and 16; an admission that contributed to his recent ban from the online platform

"I don't want to play against people that have repeatedly cheated in the past, because I don't know what they are capable of doing in the future," Carlsen wrote in a Sept 26 statement on the scandal.

For his part, Niemann recently said, "I have never cheated in an over-the-board game."

Doing so would be far from easy in a top-level tournament, where players are closely scrutinized and prohibited from keeping electronic devices like phones on them. Some tournaments even forego spectators, search participants with handheld metal detectors, or use a 15 to 30-minute broadcast delay to ensure players don't receive outside help.

Despite the safeguards, the chess world has been rocked by cheating controversies before. Tactics have included consulting with an associate or concealed phone in the washroom; or receiving instructions with the help of a hidden camera and earpiece, through Morse code or by signals from an accomplice in the crowd. A more outlandish theory suggests Niemann could even have received messages through a vibrating sex toy remotely controlled by a co-conspirator using a device to find the best moves.

Still, cheating remains relatively uncommon for over-the-board matches. Regan estimates the cheating rate to be one in 5,000 to one in 10,000 for in-person International Chess Federation tournaments, representing about five to 10 credible cases per year. By contrast, he calculates the cheating rate for online games to be significantly higher, at one to two per cent.

"There are a lot of cheaters around," Drkulec added. "But usually they're online, and the platforms are catching them. But they're also catching some people who aren't cheaters, who just improved a lot quickly."

Drkulec says he has seen several players falsely accused of cheating after making significant progress by practicing online during the COVID-19 pandemic, when in-person tournaments stopped. Only in-person games factor into International Chess Federation rankings.

"A lot of kids were really working hard during the pandemic, and now they're upsetting the higher-rated players," Drkulec explained. "Niemann is only 19 and he was invited to the tournament for a reason, because he's had a very rapid improvement."

With files from Reuters.