Odds and Outs

Calculating the pot odds required to call a bet is a skill that every poker player needs in their mental toolkit. You can perform these calculations in your head, but it takes some practice to perform them quickly. You don’t need to be exact… a close estimate is good enough. Next are a couple of examples that explain the process.
Example 1: Let’s say that you have a flush draw on the turn. Your opponent shoves all in, and you assume that he has you beat at the moment. Should you make the call?
It depends on the odds of making your flush compared to the pot odds that your opponent has given you. You have 9 outs to make your flush.
First estimate the probability of making your flush. Use the “rule of 2” when there is one card to come. Multiply the number of outs by 2, and your estimate will be that you have 9 * 2 or an 18% chance of making your flush on the next card to come. Now the harder part is to convert that to odds. Subtract 18 from 100 and you get 82. The odds of making the flush are then 82 : 18 which is roughly 4.5 : 1 (82 / 18 = 4.55555). If the pot odds are greater than 4.5 : 1, then you should make the call.
If the pot has 200 in it, and it costs you 40 to make the call, the pot odds are 200:40 or 5:1. Therefore you should make the call. You will only make your flush 1 in 4.5 times, but you get paid 5 times your investment, so in the long run it is a winning play.
Example 2: You have a open ended straight draw on the flop. Your opponent shoves all in, and you assume that he has you beat. Should you make the call?
It depends on the odds of making your straight compared to the pot odds that your opponent has given you. You have 8 outs to make your straight.
First estimate the probability of making your straight. Use the “rule of 4” when there two cards to come. Multiply the number of outs by 4, and your estimate will be that you have 8 * 4 or a 32% chance of making your flush. Next convert this percentage to odds. Subtract 32 from 100 and you get 68. The odds are then 68 : 32 which is about 2.1 : 1 (68 / 32 = 2.125). If the pot odds are greater than 2.1 : 1, then you should make the call.
If the pot has 200 in it, and it costs you 100 to make the call, the pot odds are 200:100 or 2:1. Therefore you should NOT make the call. You will only make your straight 1 in 2.1 times, but you will only get paid 2 times your investment when you make the straight, so in the long run it is a losing play.
More Information: The “rule of 2” and the “rule of 4” are pretty good approximations, but they become less accurate when the number of outs get high. Use of the simulator below will give you a feeling for how to adjust the “rules” when the number of outs gets high (which doesn’t happen too often in reality).
Things get a more complicated when your opponent is not all in, and there is the potential for more betting later in the hand. You’ll need to estimate what the betting might be in order to approximate what could happen later in the hand. For more information on this subject do a google search for “poker pot odds” or “poker implied odds”.
Below is a program to help you practice your mental calculations. Make the calculations in your head and check the answer by clicking on the “Answer” button (or pressing “A”). Try another problem by clicking “Next Problem” (or pressing “N”).

Test your ability to calculate the odds needed to make a call…

Question: