The most amount of chips you can lose in any given hand. The lowest remaining chip stack among players in the hand. For example, Player A has 2000 chips, Player B has 3000 chips, and Player C has 1800 chips. The effective stack in the hand is 1800 chips. The effective stack can also change during a hand. If we consider the previous example and Player C folds preflop, then Player A becomes the effective stack with 2000 chips.