What is ICM?

By Raymond T. Akers

The term “ICM” is popping up more and more in the poker world these days, and many are left wondering exactly what it stands for. Independent Chip Model is a mathematical method used to calculate a player’s overall equity in a tournament.

ICM uses stack sizes, payout data, and remaining field size to determine how often a player will finish in each position and the value of their chips at any time during a tournament. It can be a handy tool for deciding when it is appropriate to make plays such as moving all-in, calling someone else’s all-in, or how much money the remaining players should receive if they decide to chop.

A valuable example of how this varies is often given in terms of a $10 sit-and-go with 10 players, 1,000 starting chips, and payouts of $50, $30, and $20 to the top three spots. If you make it into the top three spots with your 1,000 chips you know they are worth at least $20; however, if you had only one chip it too would be worth at least $20.

To see how chip values can change depending on what players do, let’s assume that there are four players left, one with 5,000 chips (ICM value $37.18), two with 2,000 chips each ($24.33), and one with 1,000 ($14.17). If the two players with 2,000 chips were to go heads-up and all-in, one would come out with 4,000 chips and the other with zero.

While the 5,000 chip stack is now worth $38.89 and the winner in the previous example has 4,000 chips (now worth $36.44), the real winner in this conflict was the short stack, whose 1,000 chips increased in value to $24.67 without that player even doing anything.

ICM calculations quickly become very complex mathematical equations. To come up with the likelihood of someone finishing in first place, you can divide the number of chips in their stack by the total of chips in play (just one calculation). To do the same thing for 10 players the calculation total is in the millions.

The good news is that if one wants to use ICM to make decisions, there are many free online ICM calculators available.