Cheating controversy at Pro Chess League

by ChessBase
10/5/2020 – The final of the Pro Chess League was overshadowed by a cheating incident. The Fair Play Team came to the conclusion that the Armenian Grandmaster Tigran Petrosian, who played for the Armenian Eagles, the team that had won the finals and the tournament, had used computer assistance in the final. The Armenian Eagles were deprived of victory, and Tigran Petrosian was banned for life from playing on the server.

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In the finals of the Pro Chess League series, the team of the Saint Louis Arch Bishops (which had players such as Fabiano Caruana, Wesley So, Leinier Dominguez, and others in their line-up) played against the Armenian Eagles (Tigran Petrosian, Haik Martirosyan, Parham Maghsoodloo, among others). The Armenian Eagles won the final and with it 20,000 dollars, but shortly afterwards allegations of cheating were raised against Tigran Petrosian.

Wesley So was so certain that he made these allegations public. Tigran Petrosian reacted with a very aggressive and insulting response:

But investigated the allegations and came to the conclusion that Petrosian had violated the fair play rules. Some of this games are conspicuously flawless and his moves are consistent with engine suggestions. The players were monitored by webcams during the games, but during the games Petrosian often looked down, allegedly to get access to computer assistance. also came to the conclusion that Petrosian had used computer assistance during the semi-final matches. then deprived the Armenian Eagles of their victory, and declared the Saint Louis Arch Bishops the winners of the final. Tigran Petrosian's server access was deleted and he was banned for life from playing on the server.

Press release by

The Saint Louis Arch Bishops are the winners of the 2020 PRO Chess League championship. The Armenia Eagles have been disqualified from the 2020 season due to fair play violations.  

After a thorough investigation,'s Fair Play team determined that GM Tigran L. Petrosian, who played for the Armenia Eagles, violated fair play regulations during games in both the semifinal and final matches that took place on September 25 and 27, respectively. and the PRO Chess League have issued a lifetime ban against Petrosian for his actions, and per section F of the league's regulations, the Armenia Eagles have been temporarily banned from participation in future PRO Chess League seasons. 

PRO Chess League Commissioner IM Greg Shahade released the following statement:

"It's always unfortunate when the league is presented with evidence of fair play violations, but we stand behind the evidence presented from's Fair Play team."

The 2020 title is the third title overall for the Saint Louis Arch Bishops and their second consecutive championship. Both the Canada Chessbrahs and China Pandas will receive $10,000, half of the sum of the second, third, and fourth place prizes.




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Apponyi Apponyi 10/12/2020 04:50
basler88 10/7/2020 06:59 Donald trump has nothing to do with Petrosian and its offensive to say that about trump because i'm christian right
Apponyi Apponyi 10/12/2020 04:45
I thought it was a complete joke chess tourneys were happening online months ago. Like what other people have said, two cameras is still not enough. When I start otb chess again in 2021, my hope is just make sure at any means my opponents do not have mobiles in their pockets if they want to play against me.

I was a victim already of someone using phone back in 2013. But I'll make sure it happens when i return to otb after many years break.
zanzibar zanzibar 10/10/2020 04:36
@besominov Yeah I know but its clearly not the first time he's done it. He has a history with
besominov besominov 10/9/2020 09:51
@ zanzibar

Official statement on the website in question only mentions "semifinal and final matches".
This article here only mentions the final.

In the semifinal Petrosian scored 2 out of 4, losing two games, winning two games.
(The games he won look normal, getting winning position after opponent blunders.)
zanzibar zanzibar 10/8/2020 03:46
And you really think would ban him for life publicly, and take away their 20k first prize if they're not 100% sure? That's a big deal what they did to him, if you think about it.
zanzibar zanzibar 10/8/2020 03:35
It's not just the four games that Petrosian has been suspected upon. He was already cheating in the entire playoffs scoring 9/12 and a 2900+ rating perf.
besominov besominov 10/8/2020 10:27
Jobava and Petrosian also analyzed the games. (Interview is also on Jobava's YouTube channel.)
People should really have a look at the games imo before jumping to conclusions. Summary:

Game with Dominguez
Dominguez made a number of inaccuracies in a pet line of Petrosian which he has played hundreds of times and where he knows the ideas like the back of his hand. The game may have looked messy at some point for an amateur, but everything was logical and not even that complicated. In the endgame, at some point in positions where almost all the moves were equivalent and winning according to the computer, Petrosian managed to play "blunders" (according to the computer). Even playing moves that squander all the advantage and allow for a draw. ("Blundering" the win.) Not exactly a strong case for a cheating allegation, quite the opposite. Or else playing moves that are best but obvious. We're talking about professional grandmasters after all, not some random patzer.

Game with Caruana
Caruana had a winning position, then he blundered and then he lost. Both players played some good moves, both players played some bad moves. How any of this is proof of cheating for only one of the players is beyond me and I find any such claim by some "algorithm" for a game like this patently absurd. (And Caruana had a winning position.)

Game with Xiong
Standard Pirc game and again an opening Petrosian has played hundreds of times. Xiong was better most of the game. Then Xiong blundered and got a lost position. Then Petrosian blundered the win and it was a draw.

Game with So
Same line as with Dominguez, same ideas as with that game. Both sides have the advantage at various points during the game. Multiple "blunders" for both sides according to the computer. (Meaning both sides, including Petrosian, "blundering" the win multiple times.) So blundered last and lost the game. I guess this means Petrosian must have been cheating? (Sarcasm alert.)
Frits Fritschy Frits Fritschy 10/7/2020 09:43
There may have been some heated discussions in the chess com offices. Now the comments on their policy in regard to the Petrosian incident also reappeared on their site. (See: 'Nihal Sarin Survives Scare To Reach Junior Speed Chess Semifinals'.)
basler88 basler88 10/7/2020 06:59
Bravo! Armenia has a second Trump!! Both a very stupid, both are cheaters and liars, and both have a filthy mouth and no class. Still shame on you Petrosian and please change your name, you’re not worthy to have the same name as the classical World Champion!
Astuteness Astuteness 10/7/2020 04:23
Frits Fritschy is a big bonehead. That much is understood from him/her defending a cheater. Simple as that. Anyone who wants to take it light on a cheater is either a cheat himself/herself or just lacking spine.
Frits Fritschy Frits Fritschy 10/7/2020 12:28
Fgkdjlkag, for your information, the article has reappeared.
For the interpretation, we disagree, with all respect to your opinion. As a last remark: you may be right that chess com is worried about possible disrepute to chess - online chess, that is. After all, it's their money maker.
fgkdjlkag fgkdjlkag 10/7/2020 04:31
@Phishmaster, I never checked if the article was still there and do not care. Frits Frischy stated they removed the original: " and finally deleted the original article itself."

@Frits Fritschy, you are suggesting that only has 2 options: 1. to not mention Petrosian's name ever, and 2. Mention his name and not censor any comments/forum posts/etc in any circumstance. Obviously there is a 3rd option, which selected, and I gave the reasons for it. If there was no censorship, there would easily be magnitudes more coverage of it than now, whereas basically all conversation died down immediately after the censorship, and there was no major coverage of it anywhere in an exceedingly long time for the internet, until chessbase picked it up. Also notice the restraint and minimum divulging of information in the official press release, which are all designed to minimize the impact.
zanzibar zanzibar 10/7/2020 01:52
If no one on earth but the cheater knows for certain whether he cheated or not, how do you propose we catch cheaters in online tournaments?
SunriseK SunriseK 10/7/2020 12:57
His improper bullying and juvenile reaction disqualifies him immediately, even if he would be not guilty.
If he is guilty, then such reaction is also a big shame on him.
Frits Fritschy Frits Fritschy 10/6/2020 10:53
By the way, as I also wrote on that other website: I'm not defending Petrosjan, I'm just attacking the seeming lack of proper procedure. That's something that should worry everyone playing in online tournaments, even more so after our FIDE president's recent suggestion to make a regulatory connection between online chess and over-the-board chess.
Frits Fritschy Frits Fritschy 10/6/2020 10:42
In the chess com comment section there were many people asking for more evidence, like here, so I don't think they deleted everything because Petrosian had suffered enough. And that they didn't 'want to create a media storm', well, that would have been a bit late perception - any case of cheating covered by them so far had hundreds of reactions, so a mild guess is that they were aware what they were doing when they published his name in the first place.
'Also it should be pointed out that it is impossible to determine all cases of online cheating': You are completely right. That means online chess is not suited for serious competitions, unless as a makeshift replacement for serious chess in difficult times.
Frits Fritschy Frits Fritschy 10/6/2020 10:29
See About a chance of one in 2-3 billion?
A problem with this kind of software may be that it doesn't take into account how much of games is just very good homework. With good preparation, you have more moves at top level. Also, you will understand the position better than is normal with your usual level, so the continuation after the prepared moves will also more likely match computer moves. I don't know how many games of Petrosian in that event were suspicious: more games will of course increase the likelyhood of foul play. But as long as there is a possibility of the opposite, in a court of law, statistics alone won't do. 32 times the ball on red: it is unlikely, but possible.
besominov besominov 10/6/2020 09:18
I don't know if Petrosian cheated or not. Maybe he is guilty, maybe he is innocent. Only one person on earth knows the truth for sure and that's Petrosian.
I understand that none of the above points prove anything beyond a reasonable doubt. (But neither does the accusation imo, especially considering that the evidence is secret.)
Rebuttals can be made to all of the above points. I could make them if I wanted to, but I'm making an argument here.
The argument is that I find the whole affair highly suspicious.

PS: Anybody who uses the "he was looking down a lot" as an argument should be lifetime banned from any chess discussion about cheating. That's beyond farce, especially considering players can leave the room or play with a headset on. In any case they have video evidence in the Twitch interview to explain it! (Not that it matters one way or the other, just thought I'd mention it.)

PPS: While we're at the subject of cheating: you can put a hundred webcams in the room and it won't prevent cheating. Welcome to the 21st century. Human being arbiters in the room won't stop corruption but is probably the best we got. Sticking your head in the sand or ineffectual measures that in reality are a joke will only hold the chess world back.

Summary of the conclusion:
Cheating is a problem. The case against Petrosian is highly suspicious.

Who's next?
besominov besominov 10/6/2020 09:15
- US website bans a competing team to make a US team win.
- Website's popular US players are complaining after they lose.
- Immediately afterwards the cheating accusation is made.
- Website in question is both judge and executioner and the evidence (the "algorithm") is secret.

From the Jobava interview with Petrosian

- First time they publicly accuse a player of cheating by naming.
- The whole thing started with Wesly So complaining and making fairly ridiculous comments.
- They blackmailed the Armenian team by saying: if you admit you will be allowed to play in next season, if you don't admit the whole team will be banned. (They didn't admit.)
- Immediately after these "discussions" with the team manager the team and player were banned. (The next day.)
- Website in question claimed that the team signed a contract preventing them to sue them in court, but if they wanted to sue they could. (Lol, of course nobody can "prevent" somebody else from going to court, stipulating something like that in a contract would not be valid.)
- Website in question usually gives second chances, but not in this case.
- Wesly So has also accused other players of cheating after losing, like Alireza Firouzja.

Analysis of the games reveals that Petrosian had losing positions in 3 out of 4 games and blundered the win in the other one. Multiple blunders in all the games with the advantage swinging from one side to the other. The cheating accusation seems like a bad joke looking at these games.
PhishMaster PhishMaster 10/6/2020 08:59
@Frits Fritschy While this has certainly never been tested in court, the anti-cheating software relies on probabilities, as in it is a 1 in a billion chance that you would have this many moves in common with a particular engine. Do you know what else does the same thing that is accepted in court? DNA do not be so sure that it would not be accepted in court.

People have correctly pointed out that Petrosian is not related to World Champion "Iron" Tigran Petrosian, but he was named after the world champion, who was a national hero.

@fgkdjlkag The article is still on news, and go down a bit.
fgkdjlkag fgkdjlkag 10/6/2020 08:25
@Frits Fritschy, deleted the article and all the comments because Petrosian has suffered enough already, they don't want to create a media storm, and it brings chess into disrepute if these articles get into the mainstream media. It is not because they are unsure of themselves.

Also it should be pointed out that it is impossible to determine all cases of online cheating, even if there is an arbiter in the room watching (unless the person is physically searched in addition to an arbiter).
furtom furtom 10/6/2020 04:37
I do think the article should point out that the Armenian grandmaster is no relation to his namesake, the former world champion.

I, for one, had no awareness of this person before today, and was quite confused for a moment...
thirteen thirteen 10/6/2020 03:45
'Just' the life-time ban and forever public shame to be endured by FAKE GM Petrosian is only a slap on his wrist for being some 'naughty boy' which he shows complete disregard for. But these sort of PUBLIC CHEATERS are indeed ROBBERS and are only turning up for the purpose of STEALING. Therefore these sort of 'bandits' should be criminally prosecuted, for attempted theft. What's right is right? I do hope he is reading this.
ARK_ANGEL ARK_ANGEL 10/6/2020 03:31
I am bit curious. It would be really interesting to show off the evidence before destroying a mans entire career and reputation. What were the evidence against him to justify he did cheating. I remember there was another incident accusing a player of hiding a device inside his shoes. What is more interesting here is So was the looser who accused the winner. And America won the trial and Aremania became villain's. Something fishy here. It would have been a different story if Armania lost and accused one of their top players of cheating. So this article and verdict definitely be different. Just remember the contrast reception received by Sung Yang and Justing Gatlin...
Frits Fritschy Frits Fritschy 10/6/2020 02:27
Interesting link! It should be possible to profit from it... I'll ask my accountant.
kaapski kaapski 10/6/2020 01:57

I clearly don't know much about law. Still it will be interesting to see the outcome of a court case as i don't see backing down either.

Frits Fritschy Frits Fritschy 10/6/2020 01:37
By the way,
The mentioned website first publicly named and shamed Petrosian, then closed the comment section in that article, and when people started commenting in the comment section of the next article deleted all comments relating to the case, and finally deleted the original article itself.
So it seems they don't feel quite sure about the situation themselves.
Frits Fritschy Frits Fritschy 10/6/2020 01:29
You are completely right, except for the last sentence.
I didn't know tax returns were checked with similar algorithms, but as such, they would not be accepted as enough proof in any court I know of. And they are (still) not seen by FIDE as enough proof in over-the-board chess; there should always be supporting evidence. Just like DNA matches in itself are not accepted as enough proof in criminal cases. Moreover, in court cases the methods of collecting evidence should be available to the accused party.
Of course the results can be a starting point for further research; in over-the-board chess by searching for forbidden means of communication. And a civil court would probably see the refusal to comply with these researches as enough supporting evidence. But I doubt very much that an independent judge (which chess com isn't) will see 'glancing downwards' (as was said about Petrosian) as enough, even when he is 'sleazy and unpleasant' or is accused by a 'high level GM'.
kaapski kaapski 10/6/2020 12:50
Petrosian probably doesnt realize how good the anti-cheating software is and there fore thinks he has a chance by retaliating like this.

My guess would be is using anti-cheating software which as a first line has a probabilistic algorhythm as a screening tool and if a player is suspected evaluation wit multiple engines follows.

As you can see in thuis article these techniques already existed 10 years ago and since then probably have only become better to the point of being almost infallible.

Similar algorhythms are also used to check if you cheat with yout tax returns from for example.

I think chances are slim that will publicly show additional evidence ( cause they dont want their algorhythm in the open), but probably in a court of law Petrosian wouldnt stand a chance.
John Maccormack John Maccormack 10/6/2020 12:35
Where can I find the game to replay it? JXM
chessbibliophile chessbibliophile 10/6/2020 10:37
This Petrosian is not a son of the late former world champion. They only have their names in common. The former world champion weighed his words carefully when he spoke or wrote. Like other human beings he too had a share of bad qualities. However, he was civilised towards both friends and foes. It's a pity that Tigran L. Petrosian has alienated neutral readers who are not on either side with his abusive language. Meanwhile we have yet to see the evidence that would establish who was right and who was wrong.
JoeCJK JoeCJK 10/6/2020 10:07
Cheating allegations aside, my first impressions of Petrosian is not very pleasant. It's just something about his look and demeanor. First impressions is that of a sleazy and unpleasant male. He didn't do well to improve this perception by responding in such a coarse and piggish manner.
leshanth leshanth 10/6/2020 09:29
Such a legend would never do that he was tigran petrosian the world champion' s son this really breaking news
leshanth leshanth 10/6/2020 09:27
In the youtube channels gotham chess international master levy also discusses this in his video and also hikaru of course we know who he is so first when I saw the video I was shocked and thought he was not cheating but after this article I am totally shocked and as garbage tolled that I wonder the definitive evidence that they acted upon to ban him same for me
gabeeg gabeeg 10/6/2020 08:54
I am curious to know the definitive evidence that they acted upon to ban him, but I trust they have him dead to rights. High level GMs are not going to make accusations like that (and public) lightly. In any case it is a shame he will have to live with for the rest of his days as a chess player. I am also disgusted in his 12 year old like response to the accusation, I would understand being angry or offended...but his response lacked any maturity whatsoever. I feel bad for the teams the beat and I feel bad for Petrosians team mates if they were uninvolved, a great honor taken away and a taint on their reputations. He made a selfish and extremely poor decision.
Gerald C Gerald C 10/6/2020 08:35
T. Petrosian and priorly, 6 months ago, Andriasyan and Sarsyan ... That's much for a small country !
fgkdjlkag fgkdjlkag 10/6/2020 06:57
Agree with the other commenters: it would be nice to see the evidence, but will not reveal it. Be that as it is, it's hard to see how this should affect GM Petrosian outside of, because no one outside can really say if he cheated, unless the team at shares their data with other organizations/organizers, etc.
That's a great point by tomohawk52, the semi-final team that lost should actually have advanced. Maybe since it was the first time was in this situation, they had no plan on what to do.
Aighearach Aighearach 10/6/2020 06:53
An innocent person would be angry, but would take the accusation seriously. His response is aggressive and insulting, and also dismisses the idea that cheating is bad, implying that the person complaining about cheating perhaps didn't cheat hard enough. That's what it means when you talk about babies and diapers and such things in response to cheating allegations; it is not in any way a vigorous defense of oneself.

And of course, OTB he isn't nearly as good.

@Paris Beau: Right, the computer tells you this, and it seems that way if you have computer helping you do analysis.
John Maccormack John Maccormack 10/6/2020 02:06
Where can I see the game? Can't find it on Thanks JXM
tomohawk52 tomohawk52 10/6/2020 02:06
I understand that for these elite tournaments the players must have a camera watching them and their surroundings. Is audio surveillance also a requirement? If not what stops someone from watching the game in an adjoining room, following the game online in real time with an engine, and literally yelling the moves to the player?