The independent chip model (ICM) is the most common model used in poker tournaments to evaluate your chip stack. Let me introduce the basic concepts in this article and keep all mathematical aspects to a later article.
ICM – Why do we need it?
The main reason you need a model like ICM is because in tournaments you dont get awarded for winning chips, you get awarded for outlasting your opponents.
Given the current stack sizes and given the payout structure, ICM returns you the current value of your stack in real money.
ICM – Math behind it
The math behind it is a lottery model where each chip is awarded as a ticket into a lottery. According to the number of “tickets” you get an expected payout. I will write some follow up articles to go a little more in depth.
ICM – Big Tournament Fields
The computational resources grow more than exponentially (actually factorial) with the number of entrants. This is why it is very unpractical to run large calculations on big tournament field sizes. It is much easier to get a feeling for smaller tournaments – ideally even just sit and goes. Than take your general knowledge and feeling and try to apply it to bigger field sizes.
ICM – Getting a feeling
Let me be straight up honest: It is not that important that you know how to calculate ICM. What really matters is that you develop a felling for when ICM starts to kick in and how it affects your ranges. As discussed above it is very unpractical to do calculations for large field sizes with current computers, the best way is to practice and develop that feeling in sit and goes.
A great way to learn ICM is to use software tools. My personal favorite is SNGWizard. I suggest you try out their trail version and do a ton of quizzes to get a feeling for ICM ranges for various stack sizes and payouts.
ICM – How it affects your ranges
As some very general rules, ICM shifts pushing ranges to be wider and calling ranges to be a lot tighter. I hope this helps you as a start, but it is crucial you develop a good feeling.
ICM – Summary
ICM is a model that converts your chip stack in a poker tournament to a real money amount given all other stack sizes and the payout structure.