ICM Confusion On The Bubble

    • hoagy
      Joined: 21.10.2014 Posts: 81
      I've been playing SnG using the ICM theory to gain some real rather than simulated experience of the mathematics involved in it. I noticed some inconsistency in certain circumstances which encourage me to be careful about depending on it.

      In hands I played using the ICM I was frequently granting more value or equity to the short stack than they actually held. The ICM calculations don't seem to consider the stack size of the next player who will post the big blind. In my standard play if the blinds are large and the small stack has to post the next big blind I would factor into my move that the short stack could be committed and have to call any all-in on the next hand with any two cards. By strictly applying the ICM I lost some games by not considering that.

      While playing as middle stack using the ICM means of calculation I gave less value or equity to some of my hands than they actually held. Strictly adhering to the ICM I played and lost some hands in that situation, whereas in my standard play I would have folded and just outlasted the short stack.

      When the blinds are large individual equity or value changes significantly by the chips posted blind, even if a hand is not played the small stack loses equity while the medium and large stacks gain. What is the allowance or consideration for that in the ICM method? If that is not considered correctly is the ICM method not more effective towards the outcome of the current hand rather than that of the overall tournament?
  • 1 reply
    • ghaleon
      Joined: 17.10.2007 Posts: 5,877
      ICM only calculates value for stacks in current hand and e.g. nash ranges are then formed from that information. Nash does not account any future game situation like how blinds will be affecting in next hands. Because of future situations you might want to be lot tighter with small stack if you are not first one to be eaten by blinds. Situation called "folding war". Also with small stack there are situations to make call that you know to be -EV itself. E.g. you are BU with smallest stack in 9man bubble. CO chip lead shoves wide to abuse bubble. In here with stack that would not generate fold equity with open raise you get protection from chip lead shove as even when you call it will be tricky for middle stacks to overcall. Often middle stacks will be tighter than they should be.

      Also one classic situation to apply FGS (future game simulation) is when you are in early position with like 3-6bb stack. You often still have fold equity by making shove or nonallin play, but blinds coming will hurt your stack a lot. So it makes sense to shove wider to maintain your fold equity for suture situations. Though some players go way overboard with this,