Counting Poker Outs made Simple | Rule of 4 and 2

So, what are outs in poker?

In poker, you often find yourself after the flop or turn, holding a hand that is not strong but has the potential of improving into the winning hand. This type of hand is called a drawing hand, and the cards that improve it are called outs.

Determining how many cards from the deck improve your hand (or how many outs you have) is fundamental. It is the first step toward deciding whether to continue with your hand and, if so, how to play it. This is because your outs allow you to estimate the likelihood that your hand will improve after one or two cards.  We will see how to use the rule of 4 and 2 to make quick estimations of that probability. Then, you can make correct, informed decisions on how to play.

Let’s tale a look at an example.

You are holding K♥9♥ and the flop is A♥7♥8♣, so you only have Ace high at the current time… However, if a heart comes on the turn or river, your hand will be upgraded to the nut flush! The remaining hearts in the deck are considered as outs.

In this example, to figure out your outs, you must count how many hearts remain in the deck. There are 13 hearts in total. You hold two, and there are two more on the board. Therefore, there are nine more hearts left among the unseen cards (considering both the remaining cards on the deck and your opponent’s cards that you know nothing about). These nine cards that improve your hand, making it a probable winner, are your outs!

Outs Cheat Sheet

Hand Board Outs Description
J♥T♥ K♥Q♥2♠ 15 Flush draw and open-ended straight draw
A♣3♣ K♣7♣2♥ 12 Flush draw and an overcard (or flush and inside straight draw)
K♦7♦ A♦J♦2♠ 9 Flush draw
T♦7♣ 9♥8♠3♣ 8 Open-ended straight draw
7♠7♣ J♥7♥2♥ 7 on the flop, +3 on the turn Set to make full-house or better
J♥T♠ A♣87♠ 4 Inside straight draw
8♠8♥ A♥9♦6♠ 2 Pocket pair to make a set

Counting outs is not always trivial

Estimating outs in some circumstances may require some further study of the situation. Depending on the situation, not all cards may count as full outs. Depending on the board, some outs may give an opponent a better hand.

For example, you may be drawing for a flush, but some of your outs will pair the board, potentially giving an opponent a full house. Also, you may be drawing for a straight, but, if there are two cards of the same suit on the board, some of the outs may give an opponent a flush. In situations where you think that some of your outs may be compromised, you can adjust accordingly, and count them as less than whole, half for example. Based on how the hand has evolved and how your opponents have acted, you may be able to evaluate your opponent’s range of hands and figure out if your outs are good.

So, what is the rule of 4 and 2?

Using outs to quickly estimate the probability of improving your hand on the turn or river is essential to becoming a good poker player. The rule of 4 and 2 is a trick that can be used for working out an estimation of that probability very quickly.

Phil Gordon first invented the rule of 4 and 2 in the “Little Green Book.” It boils down to the following.

To make a quick estimation of the probability (percentage) that you will hit one of your outs, you must

  • With one card to come, multiply your outs by 2 (from flop to turn, or from turn to the river)
  • With two cards to come, multiply your outs by 4 (from flop to river, useful in all-in situations when no more betting is to be considered).

First Example

You hold J♦T♣ and on the turn, the board is K♥Q♠5♦3♣, you have an open-ended straight draw, so 8 outs. As there is one more card to come, you can multiply by 2 and estimate the probability that you will make your straight to 16% (as we will see later, your actual equity is 17.4%).

Second Example

You hold A♦9♦ and the flop is K♦T♦5♣. Your opponent moves all-in. You have a flush draw, so 9 outs, and with two cards to come, you have about 9*4 = 36% chances of making your flush.

The rule of 2 and 4 calculates only approximatively the percentage of hitting your outs. The more outs you have, the less accurate the approximation is. Let’s take a look at some examples.

Accuracy of the rule of 2 and 4

Outs Flop to turn, rule of 4 and 2 Flop to turn, actual percentage Flop to river, rule of 4 and 2 Flop to river, actual percentage
4 inside straight draw 8% 8.5% 16% 16.5%
8 open-ended straight draw 16% 17% 32% 31.5%
9 flush draw 18% 19.1% 36% 35%
12 flush and overcard 24% 25.5% 48% 45%
15 flush and open-ended 30% 31.9% 60% 54.1%

Some Examples

  • you have a gutshot straight draw on the turn, so 4 outs and one card to come. Using the rule of 2 you estimate that you have 8% of making your draw. The actual percentage is 8.7%, so there is a difference of -0.7%
  • you have a straight draw on the turn, so 8 outs and one card to come. Using the rule of 2 you estimate that you have 16% of making your draw. The actual percentage is 17.4%, so there is a difference of -1.4%
  • you have a flush draw on the flop and facing an all-in bet, so 9 outs and two cards to come. Using the rule of 4 you estimate that you have 36% of making your draw. The actual percentage is 35%, so there is a difference of +1%

In a nutshell

Knowing your outs gives you a better understanding of the value of your hand and of the probability that it will improve. The rule of 2 and 4 is a useful trick to make a quick approximation of that probability. The next step is to learn how to use your outs to make informed decisions and improve your game! To do so, you can check out the tutorials on expected value or pot odds,

Please leave any comments or questions that you may have. You can also visit our recommended poker sites page, to see where you can start playing safely, for play or real money!


This was the last tutorial of the Basic Poker Strategy Course. Congratulations on completing the course!

You can now pass our Basic Poker Strategy Quiz, or try out your skills for play or real money to one of our Recommended Online Poker Sites 🙂

10 thoughts on “Counting Poker Outs made Simple | Rule of 4 and 2

  1. Your article on “Outs” which thankfully you explained was the first I have seen on this angle of making the decisions for playing poker. So many people expect you to know what they are talking about. and sometimes we don’t. 

     It was interesting and explains another way to make better bets.  The old “Know when to hold’em and Know when to fold’em” explained a little more.  While poker is a game of chance, is really a fun game of strategy as well.  While I won’t be playing poker anytime soon, I will enjoy having your article to return to and refresh my memory when the opportunity comes.  Thanks for sharing, Sami

  2. Alway good to find a more simplistic way to remember information and when it comes to poker it is very easy to make stupid big mistakes. 

    The rule of 4 and 2 certainly makes close estimates of the actual flop to river percentage.  

    Read it several times and now understand completely. 

    Thanks for the valuable information. Good luck at the table!

    1. Yes, on the tables you cannot make exact estimations. The rule of 4 and 2 is very easy to apply, sufficiently accurate, and therefore very helpful! Best of luck to you too!

  3. I have very little experience with poker and it is clear that I have a lot to learn. What I am seeing is that there is a whole other level of skill that goes into poker that I hadn’t realized before (probably why I am not that good at it!). It’s crazy how the odds come in so handy when trying to figure out how to get the best hand. How long did it take you to learn all of this and be successful with it?

    1. Hello Steve. Personally I started reading poker strategy books as soon as I discovered poker as I was very interested in understanding the basic principles of the game. Don’t be intimidated, the basic principles are easy to understand and practice! Check out the Basic Strategy tutorials and you will be on your way of mastering the game 🙂

  4. Nice article.  

    I actually don’t know how to play poker myself and so any tips or insights I can get I find to be helpful.  

    Do you have any articles on how to play poker for beginners?

    Do you play poker regularly with people or do you play online?

    Thanks for the great tips my friend!

  5. I will be using the rule of 4 and 2 next time I play my mates at a party. I can’t say I’ve had luck with poker but after seeing this site which I have bookmarked for future references and strategies. four of a kind or a straight flush is on the way. 

    Many Thanks 

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