Pot Odds

As you know, odds are a constant presence in poker. There are the odds of hitting a draw, the odds of getting an Ace or a King on the flop, the odds of hitting three of a kind when holding a pocket pair. All those situations can be analyzed through probabilities.

Probabilities are often expressed as percentages. Therefore, odds of hitting at least a pair of Aces or Kings on the flop when holding Ace-King are about 32% - meaning you'll get there 32 times out of a hundred tries.

Knowing your real chances of winning the pot is particularly important when you have to decide whether or not to call your opponents bets. Let's take a look at the situation as follows:

A 10-player Sit & Go game with 6 players left. Starting stacks 1,500. Blinds 50-100. Everybody folds to you on the button, with a 4,200 stack. You raise to 300 with 8Club-10Club. The big blind calls (1,800 stack when the hand started)

Flop is AClub 5Club 2Coeur

Your opponent checks. You decide to bet 400. Your opponent reacts by going all-in for 1,500 total!

Having closely observed this player before, you're pretty sure he's holding an Ace, possibly with a medium kicker. You don't think he hit two pair, since he's a tight player who sure wouldn't have called pre-flop with A-2 or A-5. So, basically, there's almost only one way for you to win the pot: hitting a flush on the turn or the river. What are your odds?

If you remember our article about flopping a draw, we know that that you have about 37% chances of winning the hand.

Should you call?

Let's assume your opponent is holding A-J: here is how to calculate your expected value on this hand.

The pot is (300+300+50+400+1,500) = 2,550, and you have to call (1,500-400) = 1,100.

So you're facing a bet of 1,100 to call in order to win a 2,550 pot. Therefore, you have to call (1,100/[2,550+1,100])=30% of the expected return on investment (including your bet).

You need to compare this 30% figure to the 37% chances you have of winning the pot. Since 30% is less than 37%, you can conclude that the winnings justify the risk.

This kind of calculation is a crucial aspect of poker. You should not hesitate to reread the above example again in order to make sure you have understood correctly.

Another way of explaining the relation between odds of winning and odds of losing is to transform the percentages into simple odds. What am I talking about? Let's go back to the example shown above, where you had 37% chances of winning with your flush draw. Here, you have 63% chances of NOT winning (including slim chances of splitting the pot). So your odds are 37 to 67. Simple! In order to compare those odds, you have to convert them into a simple base. It's not complicated at all: you just have to notice that 16 to 8 is similar to 8 to 4, or 4 to 2 – and finally 2 to 1, the most simple form in which all odds are written. As a result, 37 to 63 will be noted 1,7 to 1 (63/37=1,7). A coin-flip has 1 to 1 odds (exactly 50%).

It has to be noted that pot odds do not show which player is the favorite to win the hand, since the format will always be “ something to 1” (or in certain cases “something to 2” or “something to 3” – if you want to avoid using decimals, you'll usually say “5 to 2” rather than “2,5 to 1”). The context of the hand will usually tell you who's a favorite.

Why use pot odds rather than percentages? It's just a matter of habit and preference. The way you do mental calculations will influence your personal choice.

Players who use pot odds know them for the most common situations, rather than their equivalent in percentages. For example, they know that a flush draw with two cards to come has about 1.7 to 1 odds.

Whether you're using pot odds or percentages, get used to always comparing the price you're getting with the potential gain. More often than not in a tournament, less than average hands will have good odds for the price against a short-stacked player who just went all-in. Your opponent will be surprised by the weakness of the hand you just called with, but you know better: you did the math and concluded the price was right.