Poker is an investment game as it is a card game. It is an investment game because you invest a certain amount (your bet) on the odd that your card is better than the cards that your opponents are holding. When you invest, though, you expect a certain return on your investment. The next question would be how do you determine if you’re betting on something that will give you adequate returns?

This is where equity and probability come into poker play. Since you are holding a hand that is part of a standard 52-card deck, there are mathematical rules that rule the odds that you will be getting and on which you will base your game decisions.

Probabilities: What are your chances?

The simplest rule that you have to consider before you decide to check, call, raise or re-raise is that of probability. The probability of getting a particular desired outcome is calculated through dividing the number of possible ideal outcomes (what you want the board to reveal next) by the total number of possible outcomes (the actual number of cards from which the board card will come). This method is limited, though, by the fact that you have no way of knowing exactly what cards your opponents are holding.

Equity: What is you potential reward?

Equity refers to the number of bets that you can win in a hand, given your and your opponents’ cards and the number of cards left on the deck. Equity is what you use to justify your bet. Again the only limitation to this is that you are assuming that you know the exact card or cards that your opponent is holding.

Let us take for example in a standard Texas Hold’em game. You are holding a 10 of diamonds and a 7 of diamonds. The board has a 6 of hearts, 8 of diamonds, a Queen of hearts, and a 9 of diamonds. You have a high probability to get a flush on the next draw and in the mean time you have a sure straight which might as well be the best hand as of the moment.

So what is your pot equity at this point? If there are two other players left in the flop other than you, you will be providing more or less (more, if you bet aggressively and they merely call and less if you do the opposite and there were more people in the game when it started) 1/3 of the pot which means you have a chance of winning 67 % more than your actual bet or investment. However, before you make your move, you need to weigh this figure against the probability that you have a better hand than your opponents.