But is it teaming?

When 2 players are "working together" but not protecting each other and they will both get rewards then it is not enough proof for teaming, but when they are hanging pieces more than once and use "teammates" protection to checkmate or eat pieces, then, well, obvious teaming.

Okay, I've said my piece about what is and isn't teaming (i.e. cooperating contrary to the rules -- which means COMMUNICATING in advance). Here's an example of Blue warning Green in the Chat about a mate in 1 about to happen.  

https://www.chess.com/4-player-chess?g=10220478

They "teamed" all game.  I've no problem with most of their cooperation; everyone does it.  This is what makes FFA interesting.  It is when they chat about it that it crosses the line.

How can i know if a player i reported as cheating by teaming on chat have been banned?

That sense of justice is missing then...

Hi four player chess enthusiasts; this post applies to FFA players who are concerned about playing against a pre-arranged team, and I hope you read it before reporting players for "prearranged teaming," because probably 98%+ of the reports we get are complete bogus.

If you suspect after a game that two players in your FFA game were teaming, you can do one simple thing to help yourself send an actually helpful report: CHECK HOW OFTEN THESE TWO PLAYERS HAVE PLAYED TOGETHER. I can't tell you how many hundreds of reports of players "teaming" we've received where it turns out that one game was the single game the two accused had ever played together! Maybe the accuser could have spent 20 seconds looking at this available information themselves before sending the report! I will walk you step by step on how to use the archive for this purpose:

The Magicks of the Archive

(1. First of all, click the archive button at the top of the screen while you aren't playing a game)

(2. Suppose one of the players suspected of teaming is gustavklimtpaints; type their name into the search field)

(3. click the arrow with bar button on the bottom right of the panel to bring up the extra search features)

(4. type the name of the second player into the second name field, right below the first; it might show you suggestions of matching usernames)

(5. Let's also make sure we are searching farther back than 2 weeks: select "All" from the date list - to the right of the name field)

(6. Since we are concerned about teaming in FFA, let's select FFA from the game type list)

(7. Let's also select "Rated" or "WTA" in case these players might have played many casual games together, which would confuse our results)

(8. Looks like in this case these players have only ever played a single rated FFA game together, in which they both lost; they probably aren't very good, and they probably aren't teaming! Good to know!)

So does this conclusively show that two players haven't entered in some sort of prearranged agreement? Not exactly, they could be for example playing on many various usernames to avoid anyone else noticing two users are playing many games together; this is one reason we don't allow players to play on multiple accounts (and we monitor this by IP address). It is very hard at this point for players to actually team effectively, especially in the higher rated FFA games, as they are very easily caught. Let's talk about what most reports about "teaming" refer but which are not actually teaming. This is all likely all news if you've played FFA for a while, but this post is directed to players at all levels.

Oftentimes in FFA most threats on your position will be made by the players to your left and your right, especially in the early to middle part of the game; you can think of how difficult it is for the player across from you to threaten your position: their Knights are very far away, their Bishops would have to zig zag through dangerous enemy territory to threaten a square across the board, their Rooks are likely stuck behind other pawns \ pieces for a while; and it is unlikely they will move their queen near you where you can threaten it, while the other two players will create other threats against them. THEREFORE IT IS A NATURAL CONSEQUENCE OF THE GEOMETRY OF THE BOARD THAT MOST THREATS WILL COME FROM THE SIDE PLAYERS. Anytime your left player can check you, capture a piece, create a threat on one of your pieces, or even create the threat of a threat, it gives an opportunity to the right player to create a threat of their own. You must be aware at all times of the opportunities the other players have to capture your pieces on convenient terms, check you, or threaten your pieces, and do your best to stay one step ahead of them. For this reason, FFA can be very positional, but of course you cannot avoid all unpleasant situations forever; you must accept losing material at times and try to find similar opportunities on your opponents and come out ahead in the scramble, but please do not play expecting the privilege that two players are not supposed to double attack you and then report them for teaming, because in this case, it is only your own failure to understand the game! Thanks for reading my spiel.

PS: you can use the archive for other cool things like searching "All" your games and checking how many "1st," "2nd," "3rd," "4th" you have received in all your games; hest1805 has a ridiculous 1st place finish percentage! I'll let you discover other cool ways to use the archive.

I am posting this because I'm about to say what a lot of people are thinking but are too afraid to speak up for fear of reprisal by the people who run the site.  Teams or teaming is any act of deliberately leaving a piece or pieces en prise UNCAPTURED TO PURSUE A COORDINATED ATTACK AGAINST A 3RD PLAYER.  Especially if it's a free queen. I don't care if you wrote the programme for the game, you can't change that FACT. Teams are illegal in FFA. I don't need Archive, or any other statistic to spot teams. Players can decide to play teams, and it can be the only game they ever play together. You sir, are trying to sell everyone " a bill of goods " and everyone with 2 eyes that are open can see that that was TEAMS. I've lost to that same trap also, and it takes a TEAM to make that work. Otherwise, just scrap FFA altogether, just let everyone play teams, and the ones who want to play FFA can leave and go find another website that allows FFA play. 

1. You don't have to fear reprisal because we try to be fair and objective here.

2. Given this fair and objective view, if you could provide evidence to support why your definition of a team is more correct than our definition of a team, we would thus listen.

3. You haven't provided any evidence to support why your definition is better than ours.

4. Either provide evidence to suggest why your definition is better (as we have in great detail), point out the logical fallacies in our position, or if you cannot do either, perhaps consider why our definition of teaming may, by deduction, be more correct than yours.