How can playing chess nude prove you didn't cheat — and why did a world champion pull out after just one move?
Norwegian grandmaster Magnus Carlsen pulled the most "disrespectful" move there is this week when he resigned from a game against teen star Hans Niemann, Dr David Smerdon, an Australian grandmaster, said.
The 19-year-old Niemann had been accused of cheating in an earlier game against Carlsen, who had tweeted an allusion that the US player had not been above board.
Dr Smerdon said it was "an indirect but a pretty clear accusation" which was taken up by pundits online.
What kicked it off?
Let's take it back to square one.
Earlier this month Carlsen lost to Niemann, a self-taught player, at the $US500,000 Sinquefield Cup in St Louis.
The five-time grand champion withdrew from the tournament in a cryptic tweet which is generally understood to have accused the junior of cheating.
Announcing his withdrawal, Carlsen tweeted a video of soccer manager Jose Mourinho saying: "I prefer not to speak. If I speak I am in big trouble … and I don't want to be in big trouble."
Niemann said the allegations were "slander" and a "targeted attack".
"Cheating allegations are essentially the worst thing that can be levelled against you as a chess player," Dr Smerdon said.
"It can stop you getting invitations to events for the rest of the career so we're in a really serious situation."
Did Hans Niemann cheat?
There is "no evidence whatsoever" Niemann cheated, Dr Smerdon said.
But still, his reputation has been clouded, and it's this hit to Niemann's character that "most of the chess world is against the champion [Carlsen] about", Dr Smerdon said.
"Experts, I myself, have analysed all the moves, done the statistical analysis, and there are no red flags coming up at all," he said.
"Right now with no evidence of him cheating at the moment, his reputation is being called into question."
To prove he didn't cheat, Niemann has offered to play naked.
"They want me to strip fully naked? I'll do it. I don't care because I know I know that I'm clean and I'm willing to subject myself to what you want me to play," Niemann said.
He's also owned up to a chequered past — he admitted to cheating online when he was 12 and 16, which got him banned from Chess.com, but says his play is now above board.
How big a deal is it for a kid to cheat in online chess?
Dr Smerdon says this is more serious in chess than people outside the game would think, since most world champions go pro by 12 or 14.
"Here is a bit of a grey area because these people who are essentially kids, they are also professionals in our games and they're competing with the world's elite, so it's a little bit difficult to marry those things together," he said.
Why did Niemann offer to play naked?
Niemann offered to play nude to prove he hadn't had anything on him that allowed him to cheat.
There were rumours he had somehow secreted a device on his body that was able to transmit messages to him.
Playing without clothes on would show he had nothing to hide.
"Some of these allegations have been thrown around that he's managed to smuggle an electronic device that managed to get past scans — and there's this idea of where could he hide it," Dr Smerdon said.
But it's already "incredibly unlikely" a player could get away with cheating in over-the-board (in person) chess, he said.
What is Magnus Carlsen's end game?
Is it a hissy fit or protest?
Dr Smerdon said Carlsen pulling out of the most recent game could be because of Niemann's past cheating (kind of like when Australian Olympian Mack Horton refused to stand on the podium with China's Sun Yang because Yang had been temporarily banned before for testing positive for a stimulant).
Or it could be ego.
Carlsen has been gracious after losing to juniors before.
But Niemann — brash, and confident — "poked the bear" in a "taunting" post-game interview, where he said it must be "embarrassing for a world champion to lose to me", Dr Smerdon said.
"Magnus was beaten by a 15-year-old kid from India, and in his post game interview, Magnus was incredibly gracious but of course the behaviour of this junior in a game was very different to Hans.
"Hans in his post game interview was quite taunting, so I think a bruised ego probably plays a role, but also on the other hand [there is] Hans's history."
After losing to Niemann, Carlsen withdrew from the entire tournament, but in this most recent spat he's just pulled out of one game.
But refusing to play Niemann in future could force the junior from the circuit, Dr Smerdon said.
"Either you have a non-functioning event or they have to choose between inviting the grand champion and the junior, and if that's the choice Magnus is giving them, then he's essentially ruining the career of a junior."
He said the question now wasn't whether Niemann cheated.
"Nobody questions that he has the strength to beat Magnus, nobody believes he cheated," Dr Smerdon said.
"It's more the issue that, what's Magnus doing by withdrawing all the time, what message is he trying to send, and where is the chess world going to go from here?"
"At some point, Magnus has to explain himself," he added.
