You're playing against the other players' bankrolls, chip counting is counting the chips of your opponents in order to know where you stand- you must know how much everyone's bankroll is in order to know how much to bet- if you don't finish in the top 2 out 7 players per table, per session you don't advance. Being able to look at stacks of chips infront of other players is crucial as to know how much to bet, and sizing up the other players chips and doing the math and determining your bet all in 10 seconds time. You then have 30 seconds to play your hand.
