The normally placid backwaters of the chess world are foaming with controversy! Why is world champion Magnus Carlsen refusing to play young US chess player Hans Niemann, while dropping ill-disguised hints or insinuations that Nieman has been cheating? Boo! See eg here:

England’s leading female player, Jovanka Houska, accused Carlsen of “pouring more fuel on the fire” of the controversy. On Norwegian TV, Carlsen’s former teammate and aide, Jon Ludvig Hammer, called for sanctions. “It’s the most unacceptable behaviour to lose on purpose,” he said. “It’s the most unsportsmanlike thing you can do.”

Or here to see how it all started:

The 19-year-old Niemann, who has made spectacular progress into the world’s top 50, shocked Carlsen on Sunday by beating him with the black pieces. Niemann said that “by some ridiculous miracle” he had guessed what his opponent’s obscure opening would be and prepared deeply for it that morning. “Magnus must be embarrassed to lose to me,” he said.

But while many praised Niemann’s victory, others were more sceptical. They included Nakamura, the world’s highest-rated blitz player, who said Carlsen would not quit an event without good reason … “He wouldn’t do this unless he really strongly believes Hans is cheating with a very strong conviction. I think he just thinks Hans is just cheating, straight out.”

Nakamura, who is closely affiliated with the world’s biggest chess website,, suggested Niemann had been banned from playing online in the past. “That is not up for debate, that is a known fact,” he said.

Of course it’s one thing strongly to suspect that someone is cheating, but something else to have actual evidence that might stand up in court as and when the lawsuits start flying. Magnus’ refusal (so far) to say anything specific about the whole business does not look so good. But he did say a few cautiously chosen words yesterday:

Anyway, how exactly might one cheat in chess?

We need to separate out ‘live’ chess (where two players face each other OTB – over the board) and ‘online’ chess (where players play by computer from wherever they are in the world). And to note that chess computers now are far more powerful than puny humans, grinding through hundreds of millions of possible move-sequences in seconds. And to note that all serious players are part of a reasonably reliable global rating system.

These days online chess has had a massive boost in popularity because of the pandemic. And it of course is easy to cheat when playing an online game. You just need to have a separate screen or gadget opened to a chess engine that’s giving its ideas on the best moves in the position, then decide to use those moves or not. This is why for the big online tournaments the organisers instal cameras behind the players so that it’s (more or less) obvious if they have some other electronic device helping them.

That said, it’s going to be obvious that you’re cheating if you start playing top-level engine moves time after time when your record of OTB chess is at a rating that suggests you’ll rarely if ever play that well. This is one of the ways the online chess organisers in fact try to spot cheating: they’ll have algorithms that look for statistical anomalies in a player’s performance, and if a player of (say) 2200 rating regularly starts to hit moves that a (say) 2700 player might make, probably something fishy is going on.

In Hans Nieman’s case, he has admitted that when he was younger (he’s still only 19) he did cheat in online events and was caught doing so. So he comes to this murky saga with at best an unhappy record. Do old habits die hard, especially when invited to bigger tournaments with quite a lot of money to be won?

It’s in fact hard to see how cheating in online events and maybe in OTB chess can now be prevented. The core problem is that technology and miniaturisation gallop ahead. It’s no longer difficult to find a way to hide a tiny vibrating device on (or *coughs* deep in) one’s body so that an accomplice can send you code signals that point to the best computer engine moves. Maybe these devices will get so small that they evade all metal-detectors and even the most stringent personal searches. How about vibrating tooth-fillings, or biodegradable microchips hidden under your skin?

You of course don’t need to make the moves suggested by these teensy vibrations, and you might not want to do so if you can’t see why they are the best. But on the margins it will definitely help, and if you’re clever about it you will win just enough games to look as if you’re steadily improving without attracting any statistical suspicions.

A quite separate way to cheat is to hack into your opponent’s preparation before a match and know the sort of detailed lines that you might face. This sort of cheating is very hard to pull off without KGB-level technical help if your opponent is using good Internet security, and so makes sense only for matches at the highest level.

And, finally, it might happen at the highest level that someone on the close expert team supporting Player A is ‘persuaded’ by threats or promises secretly to pass to Player B the detailed files of opening variations that Player A is preparing, or otherwise to help Player B’s team get access to Player A’s prep database. Cheating by espionage rather than hacking. I wonder what helpful advice the Carlsen team got to protect themselves from all possible Russian machinations when the 2021 World Championship games were played.

So is chess doomed to be ruined by cheating?

Probably not for most purposes. Most players just want to play. And if anyone does well enough to get to the highest levels, the chances of searching statistical analysis of one’s performance increase sharply: even if the act of cheating itself is not detected or even detectable, results of the cheating will become pretty obvious. An automatic no-exceptions lifetime tournament ban for anyone strongly suspected of cheating looks like a wise move.

Maybe Magnus himself is just an automaton programmed to play at levels far above anyone else, yet still short of the top engine levels. In this latest online tournament he has put in a towering performance, winning 10 out of 15 games against serious opposition in the preliminary rounds. He could have won the preliminaries by an even wider margin. His only ‘loss’ was the game he threw in two moves against Niemann. Scroll through the moves of the game where his senior Polish opponent Duda (no relation) makes just one slip and then is obliterated. Boom.