The Rule of Four Two in Online Poker

The rule of four two…an easy way to know how many outs you've got. 

Beginner players always struggle with determining the number of outs they've got coming, and when you don't know how many outs you're playing for (or can’t figure it out in time!) you can't play statistical poker, and you can’t play with an awareness of pot odds. Basically…you can't win. 

The rule of four two is a very easy to use method of calculating the number of outs you've got at any stage in the betting, and allows you to bet draw hands correctly, and in a way sure to pay off over the long run. The four two calculator isn’t perfectly accurate, but it's usually within a percentage point or two, and is close enough to let you make accurate and informed betting decisions. 

The rule of four two is simple to apply. After the flop, with two in the hole and two on the table, you can multiply the number of outs you need to make your hand at the river by four to get an accurate idea of your statistical probability of making the hand. 

For example, if after the flop you hold a four card flush…you know that there are nine cards remaining that will you give you the needed card to finish your flush (not a bad place to be!) and to get an idea of the likelihood of getting an out card, you simply multiply this 9 outs by four, to give you a 36% chance of making your hand. The actual odds are just over 35%, so the four two rule comes pretty close. Close enough that the difference when determining pot odds should never really factor into a betting decision. 

At the turn, with only one card left to come, the number of outs is multiplied instead by 2, and not by four. So if you’re still hoping for a card to finish your existing four card flush, you know that there are 9 outs, and you multiply this by two to get a probability of making the hand at 18%. The actual probability is just over 19%, so again very close to accurate, and not different enough to influence your betting decisions one way or the other. 

Using the rule of four two gives you a great on the fly way to calculate your ultimate probability of making a hand, both after the flop and after the turn, and helps you to play smart and statistical poker, and probably to win more money.

Be sure to check out StraightFlush.com for all your online poker action.

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Byron Badd, Payton O'Brien, Gambling911.com

Originally published September 8, 2007 6:43 pm ET