Norwegian world champion Magnus Carlsen last week accused 19-year-old Niemann of cheating. "Overall, we have found that Hans (Niemann) has likely cheated in more than 100 online chess games, including several prize money events," the world's leading online chess platform wrote in a Tuesday evening report that ran 20 pages, with 50 additional appendices.
Chess.com banned Niemann on September 5, shortly after the first accusations were made, but the platform is defending itself against suggestions that it is under pressure from Carlsen, whose Play Magnus company it is in the process of buying.
After a victory in the US Chess Championship Wednesday, Niemann said the game he had just won "spoke for itself and showed the chess player that I am".
He added, "It also showed that I'm not going to back down and I'm going to play my best chess here regardless of the pressure that I'm under," but declined to comment further.