EV is sooo important at the table when deciding when to call or not. For example I have 9 10 and the flop is 783 someone bets 10 dollars into a pot of 12. If it is just me and that guy i fold, because odds are he will not call if your str8 comes. However if it is me, the man who makes the bet, and a caller or 2 then i call instantly, because the odds are that at least one of them will think that their hand is good and pay you off.EV is measured byhow much you expect to win in the end vs. how much of a bet you are calling.