An American chess star who has been accused of cheating by world champion Magnus Carlsen may have done so in more than 100 matches, a report has revealed.
Hans Niemann, 19, has previously admitted to twice cheating in matches when he was 12 and 16, but an investigation by chess.com reportedly found more cases, according to The Wall Street Journal.
Mr Carlsen, the world number one, branded his opponent a cheat last month after pulling out of a tournament after losing to him, then dropped an online match against him after one move.
The newspaper says the report by chess.com, a platform where many of the world’s top chess players compete in online matches, claims that “Niemann likely received illegal assistance in more than 100 online games in 2020 alone. These matches included contests in which prize money was on the line.”
The platform reportedly used a number of tools to detect the alleged cheating, including an analysis program that compares human moves with those suggested by chess machines, “which are capable of beating even the greatest human players every time.”
The report says some of the alleged fraud took place as recently as 2020, when Mr Niemann was 17 years old.
The newspaper says that Mr. Niemann “privately confessed to the allegations” and that he was “subsequently banned from the site for a period of time”.
The report noted that Mr. Niemann’s improvement was “statistically outstanding” but drew no conclusions about any irregularities in his in-person games.
However, he said some of Mr. Niemann’s strongest facts “deserve further data-driven investigation.” An investigation into Mr Carlsen’s allegations is also being carried out by the sport’s governing body, FIDE.
“In addition to his online play, Hans is the fastest rising top player in Classic (over-the-board) chess in modern history,” the report states.
“Getting clear on the scoresheet, Hans should be classed as a member of this group of top young players. While we do not doubt that Hans is a talented player, we note that his results are statistically outstanding.”
Mr Carlsen won the Julius Baer Generation Cup despite his resignation over Mr Niemann, after which he said he understood his “actions disappointed many in the chess community”.
“I am disappointed. I want to play chess. I want to continue playing chess at the highest level in the best tournaments,” he said.
“I believe cheating in chess is a big deal and an existential threat to the game. I also believe that chess organizers and all those who care about the sanctity of the game we love should seriously consider increasing security measures and fraud detection methods for tabletop chess.”
Mr Carlsen said he had considered pulling out of the event when Niemann was invited to take part and was blunt in his allegations against his rival.
“I believe Niemann has cheated more — and more recently — than he has publicly admitted.”
Mr Niemann insisted he had never cheated in a live game. “I could never fathom doing that in a real game,” he said.
The chess.com report states that of the more than 100 suspect games, 25 were broadcast live and that there were several prize money events.
The independent Mr Niemann has been contacted for comment.