Is Hans Niemann cheating? - World renowned expert Ken Regan analyzes

by Albert Silver
9/20/2022 – It is the story that refuses to die, and with the renewed silent protest by World Champion Magnus Carlsen it is little wonder too. Could he be justified in these dramatic gestures? The world's greatest expert on cheating detection in chess, Professor Kenneth Regan, has analyzed all of Hans Niemann's games over the last two years, online and offline, and renders his verdict.

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In view of the tremendous commotion the unraveling of the story has caused, speculation has continued to be rife. There are pitched battles in the recesses of social media with some wondering why an event such as Meltwater allows a 'cheater' to play and they do not blame Magnus for his attitudes, while others bemoan the lack of data to properly render judgement. 

Amateurs have sprung up with their own detailed verdicts, providing spreadsheets comparing the broadcast and offline event results of Hans Niemann, others doing Elo performance charts with lovely bell curves, and others running his games from events such as the Capablanca Memorial (that he won) through engines to prove his guilt beyond any doubt. As one grandmaster confided in private, "The Capablanca video is pretty damning".

The problem with all of these is the lack of scientific rigor and depth to properly make such analyses valid points of reference. On the flip side, with a lack of better sources of information, anything goes. 

Who is Professor Kenneth Regan?

Ken Regan was better known as a chess player before becoming an academic, reaching the IM title as a junior, and qualifying for the US Championship even. He explains he never planned on a career in chess, despite his talent and enjoyment for the game, and eventually obtained a PhD in Mathematics from Oxford University in complexity theory. 

In 2006, at the cusp of the infamous 'toiletgate' controversy during the World Championship, he was brought in to provide expert analysis of the cheating accusations leveraged by the Topalov Team against Vladimir Kramnik. The claims were that Kramnik's moves in Game Two, the point of bitter contention, achieved an unreal 80%+ match with the best engine of the time, Rybka. Dr. Regan confirmed this claim, but debunked the cheating accusations. He demonstrated that many of the moves that matched the engine were in fact quite forced, and if you eliminated these forced moves from the analysis, then the overall number of moves that matched engine choices was quite normal. 

Dr. Ken Regan on the cover of Chess Life magazine for his pioneering work in cheating detection in chess

Showing this greater depth and rigor in his analysis immediately propelled him into the limelight as the new top expert, even if many did not understand or accept the depth of his research. He has since been used by FIDE to supplement expert analysis in cases such as Sebastien Feller, Igor Rausis, and general oversight of major events.

Regan has developed statistical methods to prove cheating in a series of scientific papers which are accessible on his homepage.

The Interview

Dr. Ken Regan was kind enough to agree to an interview in which he not only explains how his methods work, but also the detailed work he did on the Carlsen-Niemann Affair and what his conclusions were. 

This is a slightly abridged version of the full interview (see below), removing notably some of the lengthier technical explanations.

Are broadcast games more suspicious?

In the interview I queried specific points being brought up online and elsewhere such as a possible difference between games that were broadcast and games that were not.

"What I'm saying, as justifying my not needing to take the time to individually look into tournaments to see which were broadcast and which were not, is that if there is any bias in my data, then it's towards broadcast games (i.e more of it is analyzed due to availability) and yet I show something entirely normal."

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On the quality of his system

"My system deliberately does not use specific chess knowledge, it's all based on the quantitative data from the computer's evaluations of the moves transplanted into a utility function, which is then fed into a predictive analytic model that really works in a broadly similar way to how economists base predictive analytical models on utility functions."

Screenshot of Dr. Regan's computer and the breakdown of the results

He also mentions that the system is also capable of highlighting players who are better than others at inducing errors from their opponents. Notables at this are Mikhail Tal and Alexey Shirov.

On the result in the Capablanca Memorial

You will find this dealt with in great detail, including a breakdown of Niemann's error rate, the error rates of his opponents, and how well his opponents played against him.

It turns out that not only did Niemann perform almost exactly as expected of him in terms of move accuracy, but his opponents are the ones who underperformed against him. The 0.152 on the right in blue is the error rate of his rivals.

Likelihood of a miracle in chess results

"Littlewood's Law says that if you observe a million happenings one of them will have a million-to-one prior probability. which is the common definition of a miracle. So if you see a million things a day, then a miracle happens every day. And in online chess a million games per day is the norm."

The verdict

Dr. Regan analyzed all of Hans Niemann's games over the last two years, including online games, such as played on and their events, and his conclusion is there is no reason whatsoever to suspect him of cheating. The wide range of results in a bell curve, with some good and some bad, is actually a sign of a healthy distribution of results. Many of the so-called points of suspicion are in fact quite normal and suspicion is really the result of faulty analysis by zealous amateurs. Even online his play has been quite devoid of anything unusual.

Full results of his data can be found at this link

Full interview

Here are a few mainstream news reports:

Born in the US, he grew up in Paris, France, where he completed his Baccalaureat, and after college moved to Rio de Janeiro, Brazil. He had a peak rating of 2240 FIDE, and was a key designer of Chess Assistant 6. In 2010 he joined the ChessBase family as an editor and writer at ChessBase News. He is also a passionate photographer with work appearing in numerous publications, and the content creator of the YouTube channel, Chess & Tech.


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Kyriosity Kyriosity 2/13/2023 10:38
For Niemann haters:
1) hasn't revealed that much of chessmasters used to cheat online, assummed this to after a warning. Why didn't publicated their chats but only of Hans ?
2) there're indian GMs who woned Carlsen online but lost on-site.

For Carlsen lovers:
1) Magnus likes football, and now imagine Messi that after 5 mins of game accusses a player from opponent team of being on doping and quits.
2) Imagine Magnus playing for fun chess with boys and girls in a park and then out of a sudden a father of one grabs his kid away, publically announcing that he is a pscychologist and is sure that Magnus is pedophile.
3) Magnus is a member of Norwegian chess federation, the head of which has admitted that, yeah, had cheated once online. Where are the principles of that Magnus?
casperradil casperradil 12/26/2022 08:53
The chance that all of Niemann’s performances of his live games in the 19 season were all over 2500 while all of his non-live games were under 2500 is very close to being one in a million. So maybe Regan’s analysis can should be redone!
Talhaunted Talhaunted 10/7/2022 01:07
If Carlsen says he is cheating, ask him why he thinks that. Contrarily to most of the comments I read from people who do not realize the importance for chess of that issue at this very juncture where it becomes obvious that kind of cheating has the potential to put an end to the integrity of the game. A total different methodology is needed to address what is turning into a major challenge to the integrity of the game.
MagoPINK MagoPINK 10/5/2022 05:38
Naaaaaa. Hans Stockfish NeinMann is NOT cheating.
tauno tauno 9/28/2022 11:22
@Jacob, thanks a lot! The cheating drama starts at 19:30.
lajosarpad lajosarpad 9/28/2022 09:59
@Jacob Woge thanks for the link. I will look into it.
Jacob woge Jacob woge 9/27/2022 05:24
"I don't know what Caruana said about him, but I doubt that Caruana's opinion would be a proof. If I'm wrong, please quote Caruana"

It's not until a bit into the 1h14m podcast that they get into the nitty gritty, but here it is:

Select "UNFILTERED LIVE MEETING - Drama, Cheating, Chess 960 w. Caruana & Chirila"

This is from Sept 21st, I believe(!) there is a recent update
lajosarpad lajosarpad 9/27/2022 05:13
@klefticuf I watched the video and it provides factual arguments for why one might think that Niemann was cheating. Yet, as you also confirmed, it's not hard evidence. Yet, we should not call someone guilty without hard evidence, even if there are allegations against him and even if he committed offences in the past.

The argument that someone does not play against an ex-cheater for being afraid of his future possible offences is implausible. Even jailed people are released after they serve their sentence. And online cheating, however serious it is, it is nothing in comparison to what people are incarcerated for.

So, in my opinion if there is hard evidence, then it should be presented and the cheater should be caught. If there is no hard evidence, then the accusation is baseless, even if someone has reasons for suspicion. Escalating a suspicion into an accusation is a very serious matter and if we approve Carlsen's so doing, then in the future any strong player will be more inclined to baselessly accuse some people if they have surprisingly good results. Morphy would probably be accused of cheating nowadays.
lajosarpad lajosarpad 9/27/2022 08:18
@klefticuf I will watch that video, thanks for sharing it. I cannot watch it at the time of this writing, but I will leave a comment here after I watched it.
klefticuf klefticuf 9/26/2022 01:11
@lajosarpad: I urge you to watch the Lets check analysis. It doesn't prove that he cheated in the Sinquefield Cup but it goes a long way to prove that he has regularly used an engine in the past 2 years....
lajosarpad lajosarpad 9/26/2022 12:50
@withcheats_youlose you strongly suspect Niemann of cheating. You have given the reasons of your suspicion, which can be summarized by

- he cheated previously twice
- Caruana said something about him
- he claimed that he prepared Be6
- he made mistakes during his board analysis

Let me break down to you point-by-point:

- the fact that Niemann cheated twice before in online chess does not prove that he cheated against Magnus in the Sinquefield Cup
- I don't know what Caruana said about him, but I doubt that Caruana's opinion would be a proof. If I'm wrong, please quote Caruana
- Grandmasters prepare a plethora of lines including, but not limited to lines their opponents played. One of the main goals of preparation is to prepare suprises for the opponent, traps, offbeat lines and novelties. So you can rest assured that both Carlsen and Niemann prepared offbeat lines their adversary never played before
- playing a game is very different from speaking about the game. While one speaks about his/her game, he/she has to concentrate on his/her sentences, focus on questions, etc. In short, analysis is very different. If someone is doing poorly in the post-mortem analysis, that does not mean that the good moves played by the player were suggested by a computer. If all the poor post-mortem analysis of strong players would be treated as a proof for cheating, then most of the GMs would be accused of such, as most of them has spoken some rubbish during analysis

So, the reasons you have given are explaining why you think Niemann was cheating, but they do not come even close to being a proof. Nevertheless, this does not exclude the possibility that Niemann was cheating, but I have not seen any convincing evidence so far.
withcheats_youlose withcheats_youlose 9/26/2022 12:28
Forget all this statistical nonsense from quack doctor Ken Regan, a self-proclaimed expert in anti-cheating, who can't seem to catch the most evident cheaters, just listen to what Fabiano Caruana said about him. I will try to simplify all of these ramblings: Hans Niemann is a fraud.

The facts are that Hans Niemann has himself admitted that he has cheated two times in online chess, or better yet, he has been caught cheating online, at least, two times. In his post-game analysis during the Sinquefield Cup, he surprisingly said he had miraculously prepared that day Be6 move and even further against Carlsen, an offbeat line that Magnus Carlsen never had played before. The next day after Carlsen had withdrawn, his board analysis, without computer evaluation, of his drawn match against Firouzja is ridiculous. For the sake of truth, all his board analysis are piss-poor and incoherent.

If nothing is done to stop this chess fraudster, only bullet chess will have any credibility in the near future.
klefticuf klefticuf 9/26/2022 11:09
Convincing ? I would like to see the "Let's Check" analysis for some other players.
If it is indeed true that no other game has recorded a 100% result and Niemann has 10 of them in the last 3 years, statistically, that's over-whelming.
lajosarpad lajosarpad 9/24/2022 02:08
@tauno even worse. If you have the wrong political views, then you are banned for your world view. But, if you strongly suggest that a fellow chess player is cheating, without providing any evidence, then you get away without being officially warned or criticized by FIDE, at least if your name is Carlsen.
tauno tauno 9/23/2022 10:14
@arzi. You're right, there are rules. But what happens if you break them? Nothing, it seems. The show goes on. It's business as usual.
arzi arzi 9/23/2022 07:18
These tournaments were not fide tournaments and you can behave like Carlsen. We can now quit this bullshit and move on.
arzi arzi 9/23/2022 06:43
tauno, there are fide rules. You can read about them, down there some where in previous messages.
tauno tauno 9/23/2022 02:25
At the international level, chess seems to be the only sport in the world where you can refuse to play/meet your opponent - not to mention lose on purpose - without any consequences just because you suspect him/her of cheating (or that he/she has broken the rules of the game sometime in the past). Or even worse: without giving any valid, or invalid, reason.

Let's call it a personal ban for private reasons.

But I could be wrong. Can you give an example in another sport? Tennis, boxing, football, golf?

And now we're not just talking about direct or indirect accusations of cheating after a bitter loss; it's a fairly normal, even understandable, reaction that happens from time to time in all sports.

P.S. I hope you don't misunderstand me. I really don't mind if the players make up their own rules. But you should make sure everyone accepts them before the game starts.
arzi arzi 9/23/2022 12:29
to vounaros, I don't think you understand what the main point of this thread is? Has Niemann cheated or not? If he is, then Carlsen give us evidence and no mystical Mourinho phrases.

In addition, if you give up the game and stop the tournament, you should tell the reason for it. The tournament organizers and the public deserve to be informed. They are the so-called Carlsen's employers. Niemann also deserves a solution to this mess. If he has cheated Carlsen, then he should be punished, if he has not cheated, then Carlsen should apologize for his fooling around. kicked Niemann off their site after Carlsen suspended the tournament. Carlsen's silent action has had the real effects. Did make a mistake in acting on Carlsen's behavior? That is not so simple as you seem to think, vounaros.
vounaros vounaros 9/23/2022 11:40
It's not so much if he cheated in this particular game. Carlsen and the other players cannot play against opponents that have cheated in the past so they could be cheating again. Even Aronian that was supporting Hans, in their individual game said that after a strange move by Hans he couldn't concentrate anymore... I uderstand that, you start thinking, "whether is he cheating" and then you lose concentration, and then the game... Top players shouldn't face cheaters, we want them to have the best conditions in order to produce quality games that we admire. No games for players that have cheating history in top events, it's that simple.
Graham Banks Graham Banks 9/23/2022 07:53
The poster went on: I posted a question about this incident in the lichess forum asking if anyone knew what happened with it. Apparently the post has been blocked. Maybe it’s a mistake or maybe they don’t want to discuss it. I’ll update if anything changes.
Graham Banks Graham Banks 9/23/2022 07:52
I saw this posted in the Talkchess forum: A little bit of lite cheating by Magnus, caught on a live stream.
lajosarpad lajosarpad 9/22/2022 08:17

"Btw, all comments here fall into two categories: those who believe Niemann is just a cheater and those who believe he is honest and he has just become a much better player without any cheating involved."

My comments do not fit into either of the two categories you have presented. I do not claim that Niemann has cheated and I do not claim that Niemann has not cheated. I am honestly admitting that I do not know.

But! The civilized approach to such a situation when you suspect someone of a grave misconduct is to first find the evidence and only then accuse the person. Apparently Carlsen also knows this, so, instead of accusing Hans Niemann, he displays awkward behavior, which is disrespectful to the chess fans, the organizers of the tournament (Siegman & co, for instance) and harms the reputation of chess ("kid, don't go into that chess club, don't you see that the world champ is nuts?") and creates a toxic atmosphere that harms Niemann even if Niemann is innocent in cheating (except the two known cases from his childhood).

My point is that if Carlsen wants to behave like a world champion should behave in general, then he needs to either present evidence and openly accuse Niemann, or clarify that he does not accuse Niemann and apologizes (!) for the damage he already did. The burden of proof rests on the shoulders of Carlsen. Either he proves something bad about Niemann, or he should clear the name of his nemesis.
arzi arzi 9/22/2022 10:59
Chigu: "Not to precede any judgement whether Niemann was cheating or not, Dr. Regan's method to reveal cheating doesn't hold water at all."

Surely you understand, Chigu, that Regan's method does not protect Carlsen from possible cheating accusations either? No one can prove anything with 100% certainty. It's a scientific fact. The closer the research gets to a 100% result (90.91%), the bigger the object's truth value becomes. Speculation turns into the fact.

Why don´t you do the new research about this Niemann case and show us your results? It should be easy for you.
Chigu Chigu 9/22/2022 10:33
Not to precede any judgement whether Niemann was cheating or not, Dr. Regan's method to reveal cheating doesn't hold water at all. The effect of cheating on this top level of chess is perhaps counter-intuitive. The immediate perception would be that amateurs benefit more from cheating that top players. This is true if you have means to replicate moves from a computer. But whereas complete amateurs would need precise guidance to move their pieces - which piece to where - a top player would benefit greatly from a very simple guidance regime. Even a "binary feedback" (for example, pawn vs officer) at a few critical points would be of massive help. Elite players normally recognize the top 2-5 options from for example Stockfish, but the challenge is to distinguish the perfect move from the move that weakens your position by 0.2 or 0.3 many turns forward in a complicated situation. If you know that a "pawn move" is the perfect computer move, these players would immediately understand which pawn, and can focus their brain capacity to calculate why the computer thinks this is the best move. So with very little help you can exclude many thousands of forward calculations in your analysis.

The consequence of such cheating is that the actual play would appear completely human when analyzing the play from a statistical view like Dr. Regan do. In fact, it would be almost impossible to discover such means of cheating, unless you actually catches the player in receiving such guidance (regardless of whether it's a buzzing anal plug or eye-blinking helper in the audience)

I seriously doubt Carlsen will provide evidence that Niemann cheated in the match against him, and we will never be sure whether this was a clean game. My expectation is that Carlsen will explain the redrawal from the tournament as an act of frustration, and a general standpoint that "previous cheaters" should not be invited to such events. I could be wrong in that ofcourse :)
LokeOdin LokeOdin 9/22/2022 09:34
Fact 1 : The allegation comes after a record streak of 53 games without losing. A very emotional moment.

Fact 2: Stockfish official youtube channel analysis the game as substandard. Niemann plays normal moves and Carlsen makes repeated mistakes. He played a really bad game and he seems in an amotional bad state. One mistake can loose a game. It is unheard of that players play without mistakes for years. It was about to happen, against anyone, it could have been any opponent.

Fact 3: Statistically, Magnus record streak is more suspicious than a freak loss, freak bad move.

Magnus mind cannot fathom he lost against a lowly rated young upcoming player so the only explanation he has is cheating.
arzi arzi 9/22/2022 08:14
hansj has said repeatedly that Carlsen has not accused Niemann of cheating or anything. However, Carlsen has not corrected the suspicion on the internet and in the media that Niemann cheated. This is even worse behavior. If Carlsen explains his actions later and says that his behavior was NOT connected on cheating, then Carlsen is in big trouble. He had the opportunity to stop the cheating rumors right away, but didn't. Niemann has a good starting point if and when this goes to court, e.g. in the USA. Does Carlsen have enough money for compensation?
arzi arzi 9/22/2022 06:26
It would be great to see a short final match between Carlsen and Niemann. A wet dream for sponsors and organizers of JBGC2022. What do you mean by short?
arzi arzi 9/22/2022 06:12
Yes, we all agree that Niemann didn't cheat in his game against Carlsen, even hansj thinks so, right? Carlsen had a bad day then and still has. Of course, Carlsen is upset after losing 3 games in a row to Niemann, if you count this aborted game as well. 3 lost games in a row would annoy me and probably Hansj too, to play so poorly only against Niemann, but well against others. By the way, did you know that Niemann's score in this last tournament is 2749? Has he cheated? Carlsen's score is 2928. He has to have cheated and no one can prove against that, right?
Mike Magnan Mike Magnan 9/22/2022 02:57
I don't understand this Ken. Magnus never said such a thing and you hopping on this badwagon is a little disapointing. Hans was just a MAJOR JERK after winning what should have been a fine effort. Instead ...he Pushed and pushed with um...untoward...comments. I never thought he was cheating....and probably nobody else did ...this article..(opinion) is rather moot.
SunriseK SunriseK 9/22/2022 01:10
I've also a lot of doubts the method of Dr. Ken Regan can be effective to detect cheaters in chess.
"My system deliberately does not use specific chess knowledge,..." this is bad! I believe chess knowledge is instead very important to detect cheaters. For example, usually a very very strong player (say the World Champion for instance) can put a lot of pressure and show a very strong grasp on a game, even against a super-GM opponent; but even the World Champion does at least some minor imprecisions from time to time. The contrary is quite impossible to happen, i.e. that a player in the range 2600 - 2700 Elo can put a lot of pressure and show a very strong grasp (and I would say a perfect grasp, with no imprecisions at all) on a game against the WC, like he was a super-human player with some 3200 Elo rating. No such player exists of course; the only entity that can do this, is a GM playing in centaur modality with a super - strong chess engine! So obvious...
"Dr. Regan analyzed all of Hans Niemann's games over the last two years, including online games, such as played on and their events, and his conclusion is there is no reason whatsoever to suspect him of cheating." LOL, Niemann admitted he cheated on 7 and 3 years ago; so why Dr. Regan didn't analyze such time period too?
And he found that Kramnik was not cheating, Topalov was not cheating, Niemann was not cheating, etc. I marvel if his method has found sometimes any cheating player or not. For example, has he calibrated his method over blatant cases, like Rausis for example?
Btw, all comments here fall into two categories: those who believe Niemann is just a cheater and those who believe he is honest and he has just become a much better player without any cheating involved.
But usually the truth stays somewhere in the middle: I also believe Niemann really has become a much better player, but occasionally he could have probably "rounded" his rating with some "external help".
soulblazer soulblazer 9/21/2022 11:19
Carlsen cannot handle losses, really? You must not be talking of Magnus Carlsen then! Unless for you bouncing back from a loss with wins means "bad handling of losses". Now I must stop responding in order to apply one of Mark Twain's famous quote.... Peace.
tauno tauno 9/21/2022 10:11
@Odinsgrandson. Passive aggressive or not, Carlsen has shown that he cannot handle losses. And it's not the first time something like this has happened.
After losing to Karjakin in 2016, Magnus refused to give interviews immediately after the match, and then at the press conference he left it in frustration before it even started.

And this time Carlsen didn't just lose a game. His unbeaten streak of 53 games in classical Chess was broken by a relatively young and unknown <2700 player - with black pieces! That must hurt. Especially if he was aiming to beat his own record. (The implicit accusations of possible cheating in that game are just used as an excuse and an explanation by Magnus that hardly anyone but he himself believes.)

I'm not sure if Carlsen's primary goal is to ruin a young player's entire career, although the consequence of what Magnus has done so far will inevitably cast a dark shadow over the entire future of Hans' career - and, possibly, ruin it as well. I think that in the first place it's about revenge on a purely personal level, after a painful loss. But I could be wrong: Carlsen wrote on his tweet that "beating someone once isn't revenge." And since he now seems to have no interest in trying to beat Niemann over the chessboard, he probably intends to beat him in some other way. And not just once, as he wrote. Who knows how far he is ready to go?

Regardless of whether there will be any consequences for Carlsen this time, this scandal has shown that the regulations of chess tournaments need to be reviewed and tightened.
Frits Fritschy Frits Fritschy 9/21/2022 09:38
Stop reacting to hansj.
soulblazer soulblazer 9/21/2022 09:35
Oh boy, live and let live guys. Yes, don't invite Magnus, invite Niemann and move on. Personnaly, I would invite Magnus even if he opens with 5 nights moves in all his games. :)
hansj hansj 9/21/2022 08:05
Odinsgrandson – I have not seen any insinuation from Carlsen about anything.
Cheating has not been mentioned and not even insinuated.
That is all unfounded speculations.
Marseille07 Marseille07 9/21/2022 06:25
@soulblazer I think that's what ends up happening. Carlsen can't ruin Niemann's career, it'd be the other way around - Carlsen won't be invited, Niemann will.
Odinsgrandson Odinsgrandson 9/21/2022 06:07
Hansj- you're absolutely right about "Carlsen has not accused Niemann of cheating" etc.

That is actually part of the problem here. Carlsen's actions have been very passive aggressive. He has insinuated that Niemann cheated in their match, but because Carlsen's only evidence is losing the match, he has instead passive aggressively insinuated cheating and refused to deny it.

This is unbecoming behavior.
arzi arzi 9/21/2022 06:04
Lunaticx:"What does your analysis and miracle speaking think about that ? "

At least someone is honest.
arzi arzi 9/21/2022 06:01
Odinsgrandson:"Regen can no more prove that Magnus wasn't cheating than Nieman. "

You nailed it.