Equity is your hand’s share of the pot if the hand were played to showdown from here: how often it wins against villain’s range, counting the cards still to come. You compare it with the price of a call to decide whether continuing makes money.
Every calling decision is a comparison between two numbers: the price, which pot odds give you, and your equity. Call when your equity beats the price; fold when it does not. With a made hand, equity depends on how much of villain’s range you beat; with a draw, you estimate it by counting outs — about 2% per out for the next card, about 4% per out for two cards when all the money goes in now.
Equity is always measured against a range, not against one hand. Range equity also explains why the preflop raiser bets so many flops: on K♠8♦3♣ the button’s whole range holds about 53% of the equity against the big blind’s in this course’s assumed ranges, and that edge is what a small range c-bet cashes in. Out of position you realize less of your equity, because you act first and get bluffed off medium hands, which is why the big blind defends somewhat tighter than the raw numbers suggest against big bets.
Worked example
FAQ
Is equity the same as winning percentage?
Roughly. Equity is your share of the pot at showdown, so ties count as half. Unlike the winning percentage of a single matchup, it is measured against villain’s whole range of hands and includes every card still to come.
How do I estimate equity at the table?
For draws, count outs and use the 2-and-4 rule: about 2% per out for one card, about 4% per out for two cards. A flush draw with 9 outs is about 19% on the next card and about 35% with two to come.