Ask the Wizard Column 165 Addendum
This is the unedited answer by Tony Guerrera to a question about poker collusion asked in the May 31, 2006 Ask the Wizard column.
A few common collusion schemes exist, and it is important to know about them so that you can recognize them and defend yourself against them. If you wish to enter the dark side of poker and implement them, that’s your business - not mine. Before proceeding, I’d like to say that I’m writing this for intellectual purposes only; collusion is an interesting topic worthy of theoretic discussion. My discussion will be in the context of Texas hold’em since that’s currently the most popular poker variant.
In cash games, two common maneuvers exist. In the first maneuver, the colluders trap opponents and force them to put more money in the pot than they normally would. Usually, the colluders sit next to each other; however, they can also sit across from each other. When a team member has a good hand, he signals his teammate to pump up the pot. The teammate often has complete garbage, and a sign of this type of collusion is a player who does a lot of raising on the flop and turn, only to fold on the river. In the second maneuver, the colluders also employ a betting and raising scheme. However, instead of getting opponents to put more money in pots, the betting is used to drive opponents out of pots. This isolation play is most successfully implemented by colluders sitting adjacent to each other.
If you see either of these types of collusion in a cash game, you have a few options to defend yourself. One option is to alert your casino or online poker room. However, if you feel that the colluders actually improve your EV, you should stay at the table and say nothing. For instance, if the colluders only jam the pot with monster hands, you’ll know when to get away from hands like top pair and bottom two pair. On the other hand, if the colluders are also jamming the pot with mediocre holdings, you know that you can stay in raised pots with hands lower in value than you’d stay in with against more typical opponents. Furthermore, you’ll be getting great value from them since the colluders are giving you 2:1 odds.
The two plays above are the most common plays implemented in cash games. The edges derived are marginal, especially when considering that you have to chop your winnings with your partner(s). The only way I can see colluding in cash games to be a worthwhile endeavor is to have several computers, several IP addresses, and several online poker accounts, and to simply play multiple accounts (probably no more than 2 or possibly 3) at the same tables. You don’t have a partner to chop winnings with, and if you only trap opponents with betting and reraising when you have monster holdings, it won’t matter that you are giving opponents 2:1 odds in those hands. The major online poker rooms can easily detect this type of collusion, so it’s not actually an option.
Collusion in tournament play, especially in NL hold’em, is potentially more effective. Besides the two plays discussed so far, a few additional plays exist. These additional plays can be very difficult to detect because they occur within the natural flow of the endgame. The large fields participating in most big multi-table tournaments make collusion there difficult; it’s unlikely that members of a colluding team will end up at the same table. Single table tournaments (STTs) are the killing fields for colluders. In fact, I’d be surprised if no collusion occurs in the high buy-in STTs online. Please note that I’m NOT saying that colluding is actually going on; I’m simply saying that I wouldn’t be shocked if it was.
The first play in the tournament collusion playbook is the chip dump. By consolidating all the team’s chips with one player, the team has a higher probability of getting a first place finish. With the payouts of most tournaments skewed towards first, this type of teamwork yields a higher EV for the team members even when considering that they’ll have to chop their winnings in half. If a single player is playing multiple accounts online, then he stands to increase his profit substantially. Chip dumping can be tough to detect, especially when play is down to four players. A good single table tournament player often opens all-in with a wide range of hands and calls all-in bets with a narrow range of hands. However, it’s not unreasonable to see players call all-ins with hands like KQ and KJ. Thus, one member of the colluding team can have a marginal calling hand like KQ in the big blind, and signal his teammate in the small blind to push all-in if their opponents fold. The small blind can push all-in with 23, the big blind can call with KJ, and the hand wouldn’t be questioned by the other players - they might think that the push was bad, but they’d perceive it as a standard attempt to steal blinds. The chip dump is most effectively employed when a tournament only has 3 or 4 players left. When play is 5 or 6 handed, the blinds are also high, so stealing blinds then is an important part of a winning strategy. Unfortunately, consolidating chips at this point may not provide a large advantage. The other collusion play, which does work well at 5-6 handed tables, is what I call the "pre-emptive all-in." Pushing all-in with a wide distribution of holdings to steal blinds is most effectively done when at most three opponents remain to act. However, if you have a teammate in the big blind, you can now push all-in with four players remaining behind since you effectively have only three opponents (your teammate no longer counts as a potential caller). By being the first player to push all-in, you prevent other players from entering the pot - most likely, you keep your partner’s big blind in the team’s chip count and gain a small blind in the process.
The plays discussed to this point are a good introduction to various types of plays used by colluders. The only basic issue left is the ability of colluders to share their hole cards (easily done if the colluders are playing online). Sharing cards can be a huge advantage. For example, if you hold 44, you are a 7.51:1 underdog to flop one or two 4s given that you have no knowledge (partial or full) of other cards in the deck. If you are in a pot with a few limpers, you would normally call and look to flop a set, knowing that the future bets that will enter the pot (your implied odds) make your preflop call +EV. Suppose you are colluding, and before you act, your partner tells you that he has A4. Given that information, you should now fold your 44. Many analogous scenarios exist where knowledge of your partner’s cards affects your knowledge of your odds against hitting your hand. Another instance where knowing your partner’s cards helps is when determining whether or not an opponent has a better hand. Suppose you hold T6, and the flop is TT9. Your partner folded T2. In a no-limit game, if the betting gets heavy, you normally have to worry about being against a ten with a better kicker. However, if you know that the case ten has already been folded, the only hole card combination that beats you is 99. The information to be gained from sharing hole cards helps colluders optimize their decisions since they have more accurate information regarding the state of the deck.
In short, successful colluding involves set plays and sharing hole card information. In the general sense of the term, collusion involves two or more players, but with online poker, it is feasible to collude with yourself by playing multiple accounts at the same table. By far, colluding with oneself is the optimal way to maximize your hourly profit - why split winnings when you don’t have to? The major online poker sites use software that looks for suspicious betting patters, especially between players who often play at the same table. The best way to collude is to probably do so in online STTs, making sure that the collusion occurs only as a result of the natural flow of the endgame. You would need to have about 4 or 5 accounts, along with a dedicated computer and IP address for each. Furthermore, you would have to manage the accounts such that the colluding accounts only play with each other a small percentage of the time. Even with set plays like chip dumping and pre-emptive all-ins, how you play each tournament ultimately depends on your opponents. The bottom line is that even if you are colluding, you still need to be skillful to play profitable poker.