One of the world's leading chess cheating experts says an American grandmaster at the centre of the sport's biggest scandal has shown no sign of foul play.
Hans Niemann, 19, was accused of cheating by chess world champion Magnus Carlsen after the pair played in round three of the prestigious Sinquefield Cup in early September.
Niemann defeated the world champion with the black pieces, the biggest win of the teenager's career.
Carlsen withdrew from the tournament issuing a cryptic statement on social media, before then resigning his next match against Niemann later in the month after one move.
The five-time world champion then issued a statement after winning the Generations Cup, blatantly accusing Niemann of cheating — which Niemann has categorically denied.
Kenneth Regan, a professor of computer science and engineering at the University of Buffalo in New York, is one of the leading authorities on chess cheating.
Regan, who has been a leading force on chess fair play for decades, uses a statistical model to determine the likelihood of a competitor at a certain playing level playing a move.
"Insurance companies use this kind of model to gauge the risk of damage to a home … based on the 'rating' of the neighbourhood," he told ABC Sport.
"I have a similar model where, based off the rating of the player, I put probabilities on chess moves."
Regan said his analysis of the Sinquefield Cup clash and Niemann's other games in the tournament showed no signs of foul play.
"That game and any other combination of Niemann's games are within the standard deviation of normal. So well within the usual margin of error," he said.
Regan said he compared Niemann's performance in the Sinquefield Cup to hundreds of games the American has played in recent times.
As far as the statistical model is concerned, Niemann has done no wrong.
"The spectrum of results is completely normal," he said.
This conclusion has been reached by many in the chess community, including the Australian grandmaster David Smerdon.
"Experts, I myself, have analysed all the moves, done the statistical analysis, and there are no red flags coming up at all," he told ABC.
"Right now with no evidence of him cheating at the moment, his reputation is being called into question."
Cheating scandal brings 'reckoning' to the sport
Despite no evidence of cheating against the world champion, Niemann has admitted to cheating twice in his life online.
He admitted to cheating in an interview he did in the wake of this scandal, saying he cheated when he was 12 and 16 while competing online.
In his official statement accusing Niemann of cheating, Carlsen said he believed the American has cheated more times than he has admitted to.
This scandal has brought forward a "reckoning" within the sport according to Regan, who said the boundaries between online platforms and FIDE competition will cause concern among some players.
"It will accelerate a reckoning within the chess world of the attitudes that we — now that in-person chess is returning after the pandemic — should have to those who have confessed or been caught cheating online," he said.
"Especially on multiple occasions in the case of Niemann.
"The online platforms have purview over infractions that are committed by their subscribers, whereas FIDE has the purview for in-person chess.
"Partly because of that jurisdictional ability, players like Niemann still remain in good standing with FIDE."
