On Monday, GM Magnus Carlsen surprised the chess world by announcing that he was withdrawing from the 2022 Sinquefield Cup, tweeting his decision at the beginning of round four.

I’ve withdrawn from the tournament. I’ve always enjoyed playing in the @STLChessClub, and hope to be back in the future https://t.co/YFSpl8er3u

— Magnus Carlsen (@MagnusCarlsen) September 5, 2022

At the start of the round, Carlsen’s clock was started against GM Shakhriyar Mamedyarov, but Carlsen never showed up to the board and was forfeited after the 10-minute arrival window expired.

The start of the round 4 of #SinquefieldCup #grandchesstour #chess #stlchessclub pic.twitter.com/HfSsNulsn8

— Saint Louis Chess Club (@STLChessClub) September 5, 2022

Carlsen was on 1.5/3 after losing in the previous round with White against GM Hans Niemann. According to the tournament regulations, because he didn’t complete 50 percent of his games, Carlsen’s previous results will be annulled from the tournament standing; however, the FIDE rating adjustments from these three games stand.

This is first time that Carlsen has withdrawn from a major event, and many commented that such a withdrawal from a tournament in progress for anything other than health reasons is virtually unprecedented in top-level chess. To find a precedent, one may look as far back as the 1967 Sousse Interzonal where Bobby Fischer withdrew after 10 rounds due to arguments with the organizers.

Online chess fans and commenters were quick to speculate. GM Hikaru Nakamura voiced explicit speculation that Carlsen withdrew because he suspected Niemann of cheating in their game the previous day, saying: “I think that Magnus believes that Hans probably is cheating.”

In an interview after the game, Niemann mentioned that he prepared based on Carlsen’s use of the g3 Nimzo-Indian against GM Wesley So in London 2018. However, this game does not exist, and Chess.com has not been able to locate any other modern game by Carlsen in this line. 

In his post-game interview, GM Ian Nepomniachtchi shared his thoughts on the Carlsen-Niemann game, calling it “more than impressive.”

Ian Nepomniachtchi on his game today against Wesley So, as well as his reaction to the news of Carlsen’s withdrawal: #Sinquefield pic.twitter.com/a3Sp75Df6g

— Grand Chess Tour (@GrandChessTour) September 5, 2022

After the round began, the Grand Chess Tour announced that they are taking additional anti-cheating precautions, including a 15-minute broadcast delay and increased radio-frequency identification (RFID) checks. 

As requested by anti-cheating arbiter David Sedgwick, a 15-min broadcast delay was implemented for today’s round, as well as increased RFID checks. #SinquefieldCup

— Grand Chess Tour (@GrandChessTour) September 5, 2022

Asked for comment, Chess.com Chief Chess Officer Daniel Rensch stated: “Chess.com 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.”

Team Carlsen declined to comment. 

Coverage of the 2022 Sinquefield Cup