After Magnus Carlsen's allegations, Chess.com report claims Hans Niemann 'likely cheated' over 100 times

Hans Niemann meets the Saint Louis Chess Club's new non-linear junction detector prior to the first round of the U.S. Chess Championship. Courtesy Saint Louis Chess Club, Lennart Ootes

Following on from allegations by world chess champion Magnus Carlsen that Hans Niemann was cheating, Chess.com have released a 72-page report detailing their investigation into the American grandmaster, stating that they have found over 100 instances of the 19-year-old cheating, including during tournaments that included prize money.

They did stop short of confirming whether Niemann had cheated during in-person (over-the-board) tournaments, saying that they would co-operate with FIDE, chess' governing body, who have their own investigation into the Carlsen-Niemann affair.

'Overall, we have found that Hans has likely cheated in more than 100 online chess games, including several prize money events. He was already 17 when he likely cheated in some of these matches and games. He was also streaming in 25 of these games,' the report stated.

Chess.com state that they use a range of sophisticated detection tools for cheating, including analytics that compare moves to those of chess engines.

The entire controversy arose when Carlsen was defeated by Niemann in the Sinquefield Cup in September, with the American defeating the world champion despite playing black (a disadvantage) and with perfect moves, with his post-play analysis also drawing suspicion. Carlsen followed that with a protest in their next meeting, playing a single move before resigning, and then releasing a statement with his allegations.

Niemann had responded to Carlsen's allegations by admitting that he had cheated, but only twice, when he was aged 12 and 16. The report went on to disagree with Niemann's statements, noting an instance of cheating as recent at 2020.

Chess.com, a popular platform with over 90 million members, usually handles cases of cheating and subsequent bans in private, but fell compelled to make their findings known after Niemann 'went public with their private correspondence.' The report claims Niemann admitted to cheating in a phone call with chief chess officer, Danny Rensch, while also providing screenshots of Slack conversations where the pair discuss a return to the site after his account was banned.

The site, which is also in the process of purchasing Carlsen's 'Play Magnus' app for $83 million, was at pains to point out the lack of influence the world champion had in this process, noting his non-involvement in multiple instances throughout the report.

The 72-page report also pointed out 'irregularities' in Niemann's rise in competitive, in-person chess. It claimed there were "many remarkable signals and unusual patterns in Hans' path as a player" and that his strongest performances "merit further investigation based on the data."

"Outside his online play, Hans is the fastest rising top player in Classical [over-the-board] chess in modern history. Looking purely at rating, Hans should be classified as a member of this group of top young players. While we don't doubt that Hans is a talented player, we note that his results are statistically extraordinary," stated the report.

With the high-profile nature of this controversy shining a spotlight on whether cheating in chess is commonplace, the report was keen to note that "fewer than 0.14% of players on Chess.com ever cheat, and that our events are by and large free from cheating." However, the same report notes that dozens of grandmasters have been caught cheating on Chess.com, including four of the top 100 in the world. Yet, since the site has historically not been involved in cheat detection for classical, over-the-board, chess, one cannot infer how widespread cheating is in in-person, competitive events.