Poker Collusion: What is it and how do we detect it?

“Worm and I fall into our old rhythm like Clyde Frazier and Pearl Monroe. We bring out all the old school tricks. Stuff that would never play in the city…signalling, chip placing, trapping, we even run the old best hand play.”

The movie “Rounders” depicted poker collusion at live poker tables, but online poker operators can choose to invest into effective policing of games for collusion.

Collusion in poker is any form of cheating where two or more players work together to gain an unfair advantage over the other players at the table. At partypoker you are not allowed to create a coordinated strategy with another player, with penalties for collusion including account closure and confiscation of any account balance for redistribution to affected players.

Collusion can take many forms; indeed, no two cases of collusion are exactly alike. When “soft playing”, players involved in collusion may intentionally choose passive betting lines with strong hands, a classic example would be a player folding KK when their colluding partner has been dealt AA. “Chip passing” can be a more subtle form of collusion; a player might fold a weak hand blind vs blind when it is theoretically correct to shove any two cards, and in doing so pass chips to their short-stacked colluding partner in the big blind. “Card sharing” can be effective in many game types, particularly in PLO games where colluders can make more informed decisions based on knowledge of their partners’ cards.

Challenges

Finding evidence of collusion on a network where millions of hands are played every day presents a variety of challenges in detection and as we demand a high burden of proof before acting, we typically need multiple pieces of evidence.

That preflop fold of KK is not necessarily soft-play but a mis-click.

Missing a profitable any two cards all-in preflop is not always chip passing but an inexperienced player making an understandable theoretical mistake.

The dynamic nature of tournament situations presents challenges; sometimes players should be calling with any two cards, other times they should be folding aces; collusion is often found where there is a large theoretical error, but we must first determine whether a theoretical error has been committed.

Collusion we see in MTTs (multi table tournaments) is often opportunistic in nature and perhaps there are only one or two hands of collusion, but they can be very profitable if carried out near large pay jumps, how do we find this needle in a haystack?

Detecting colluders

So how do we do it? We have built systems that highlight potential collusion by analysing many attributes of a player and their gameplay

Account level analysis

Geographical location, device linkages, shared stable or affiliate connections. These are just a few examples of account data that we use, of course none of these connections are evidence of collusion (you are welcome to play in the same game as friends or housemates, for example), but they can provide a reason to look more closely at a pair/group of players and ultimately be used as supporting evidence in order to build a strong case.

Game level analysis

How often does a player pair share the same table or tournament? We can highlight suspicious patterns with respect to game sharing. This is the simplest game level analysis we do, but there are several other systems that we have built that look at potential collusion patterns over the course of many games, but we need to preserve their effectiveness so we cannot share exactly what we are doing.

Hand level analysis

We use automated reporting to highlight suspicious hands. We determine how far from theoretically correct the line taken in the hand is and we assess whether this line is typical for this player or if it is a line taken only versus a particular opponent (likely their colluding partner). We receive daily reports of the latest hands and in combination with our historic hand history database our collusion experts use hand histories as primary evidence of collusion

What can you do?

The partypoker Game Integrity team is made up of ex poker pros, data scientists and coders. We have Game Integrity analysts whose sole job is to detect collusion. We investigate all player reports and welcome them at gameintegrity@partypoker.com where every report is reviewed by a Game Integrity analyst. We value the efforts of players in providing detailed reports and we will always reply to a player and inform them of the outcome of our investigation.

If you play on other sites, ask, what systems, processes and people do they have in place to combat collusion?

Next time

We have closed hundreds of colluders from micro stakes SNGs to high buy-in MTTs, next time I’d like to share with you how we turn the output of our detection systems into an investigation by a collusion expert, the level of proof we require, the actions taken, and share some (anonymised) details from a real case.

Nick Case
Game Integrity Senior Analyst