[Alan3]

If you are playing an optimal game without taking into account how your opponent is playing then you are playing an equilibrium stategy and breaking even before the rake. Playing at equilibrium means you force your opponents to break even no matter what action they take (unless they make mistakes by making dominated decisions -- like calling a bet on the river with the nut low). Playing optimally does not offer your opponents the opportunity to make mistakes (except for dominated decisions which are always availble no matter how you play). In order to offer your opponents the opportunity to make mistakes, you must deviate from the balancing point of optimal equilibrium -- you must tilt. To do so profitable requires that you tilt in a direction that exploits the direction in which your opponent is tilting, but in doing so you open yourself up for exploitation by another player.

This is all just theory for me though. No one really knows what an equilibrium strategy looks like in most forms of poker (two-player Kuhn poker is one form in which we do know what equilibrium looks like). But I suspect that most of the top players, Sklansky included, have a good internal approximation of equilibrium and can recognize when people deviate from it, and how to expoit those deviations.