From Wikipedia: In poker, the Independent Chip Model, also known as the Malmuth–Harville method, is a mathematical model that approximates a player's overall equity in an incomplete tournament. David Harville first developed the model in a 1973 paper on horse racing; in 1987, Mason Malmuth independently rediscovered it for poker.
Do you apply ICM to your game when you play tournaments?
I haven't been able to get a grasp on ICM if I'm being honest, but I also haven't looked into it very much. I have a basic understanding of what it is.