How do you tell if someone is a sandbagger? example included

@LDog11 It's good that someone likes statistics. It was a statistics course that finally motivated me to drop out of college.

@President_DonaldDuck As one of Lichess leading sandbagging experts (alt account here) I can confirm what number two has said that given the information you have provided it can not be determined. Since the account is new they could just be underrated since it is common with a new site to take awhile to get your rating up to playing strength.

However a sandbagger will continue the pattern mentioned and they will also.
Lose games right after a tournament ends
Occasionally play the same tournament and lose all but one or two games.
Have a rating that is constantly right below the cutoff for the arena.

Keep a watch over this account and when you report them make sure to give a good reason why in the report, mods reviewing the case normally don't do to much leg work (since they have many to review) and are hesitant to ban people as it could be a potential false positive.

Does this mean @Opendoors2_0 that when we report, we should provide more than just a game or two of reference?

Like a person losing 50% of the time to 800-1200 players, and then going perfect in a tournament?

people who suck at chess complaining that people sandbag. maybe get better? or go and play chess tournaments in real life.

I don't see why this is a problem at all.

And why should somebody who is capable of winning a couple of U2000 tournaments suddenly decide to lose in order to win a couple of U1700 tournaments?
But still, even if he does: so what, Mr President?

@Patchytoes I don't know if you are the one who reported the two sandbaggers in that bullet arena earlier. But they aren't actually breaking Lichess TOS. Now I agree they are most certainly sandbagging however lichess only prohibits "intentionally losing games" and the first games played on an account are exempt from this rule. They haven't lost any games yet and are just "playing below their strength". (The answer a mod would give if asked) Consider reporting them later when they intentionally lose games to stay below the threshold.
To your question is yes you should link a series of in tournament games saying look at this guys performance against 1700s. Then link out of tournament games or another tournament saying look at this performance now 1000 points lower.

@Denis_Gry The first law of an honorable man "I defend those who can not defend themselves"

@Sybotes Your right there is no fame or glory in winning UXXXX tournamentscompared to real tournaments, however that is all some people even have a chance at winning. To put this in perspective should we allow adults to identify as 17 year highschool students to go play on the basketball team, because who cares it's only highschool basketball.

Follow them and keep track of them for a little while. The main thing to look for is evidence of them losing many games in a row against much weaker players. Their rating may simply continue to increase and they'll be 2000+ in not too long, in which case, no harm no foul.

IMHO it's likely that they are sandbagging, and I've certainly encountered players who do this, even in U1500 arenas, but Lichess seems reluctant to take action against people as long as they aren't outright cheating unless there's very strong evidence.

@Sybotes
The reason why it's a problem is the same reason we have Uxxxx tournaments at all. They exist so that the fun of competing in and having even some reasonable chance to win a tournament is something that can be enjoyed by everyone. By allowing anyone regardless of level to have a tournament they can competitively play in, it allows more people to share in that fun and excitement and encourages more people to play in tournaments which is great for the game of chess.
When people who don't belong in a rating range manipulate their rating by deliberately losing games so they can sneak in and dominate these tournaments it defeats the whole purpose. It's also pretty pathetic that someone would have to stoop so low to boost their ego and it makes me wonder what kind of personality defect or other issues they have going on in their lives that would cause them to behave in this way.

@everyone
The good news is it was confirmed to me by an expert that my suspicions are correct and that the account in question is definitely sandbagging. The bad news is that according to the same person probably nothing will be done about it.

@President_DonaldDuck

Just tell us the handle name of your nemesis so I can send Chesscattwhite to haunt his dreams until he finally closes his account.

Who is Chesscattwhite?

Chesscattwhite is a mischievous chess semi-god who normally harasses Carlsen's haters into starting believing in the Almighty Viking King and to bend over to their Majesty: the Great Magnus Carlsen.

@P_G_M
Since accusing a specific user of misconduct is not allowed in the forums I was trying to think of a way to tell you without telling you, like if there was a way to see who won the u2000s on a specific timeslot or who is winning the most lately, but since there doesn't seem to be any way to do any of that for people who want to determine which person I am referring to I'd say to just keep your eye on the u2000's as they come up. The person in question is blowing away all the competition in terms of tournaments won. Also I'd be glad to PM anyone who requests it.