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The Rule of Two and Four
Calculating your chances of winning a hand of poker can be complicated at times. But there is an easy way to get a good approximation that can be done in the heat of the moment - even if you do not consider yourself a mathematics genius.

We saw in the last lesson how to calculate your outs in a hand, and in this lesson - concerning a trick called the "Rule of Two and Four" - we look at applying that information. The Rule of Two and Four helps you to make a calculation of your odds of winning a hand, which will in turn inform your decision on whether to call, raise or fold.
After a flop has been dealt, count your outs, then multiply that number by two to determine the percentage of making your hand on the turn, or four, to determine your chance of making it by the river. 

To put it another way: multiply by four if two cards are still to come, or two for only one card.
That figure is the approximate percentage chance of hitting your drawing hand.
Here are some examples:
1. You have  on a flop of . You expect your opponent has a hand like  - ie, one pair - and therefore you need a straight to win. You have four queens and four sevens to make your hand. That is a total of eight outs.
Now apply the formula. The percentage of making your hand is: 
On the Flop: 8*4 = 32% (with 2 cards to come)
On the Turn: 8*2 = 16% (with 1 card to come)
This is not 100 per cent accurate but it is close enough to work with at the table.

2. You have  and flop top pair on a flop of . Unfortunately your opponent holds  for two pair, so you need to catch a king in order to win. If you multiply your three outs by four, you learn that you are a big underdog, with only a 12 per cent chance of winning.
3. You hold  on a flop of . At the moment, you only have queen high, but there are plenty of outs. Any heart or six additional straight card outs will make your hand (don't count the  or  twice), meaning you have 15 outs in total. That represents a 30 per cent chance of getting there by the turn and 60 per cent by the river.  


All you need to do to apply the Rule of Two and Four is to count your outs after a flop and multiply them by two or four to determine the percentage chance of hitting your draw. Armed with this number, you can make a quick judgment as to whether you want to continue in the hand.

As ever, it will also depend on your opponents' play, and there are a great many further calculations you can make once you have grown more confident at the tables. (We discuss concepts such as "pot odds" in later courses.) 

But you should remember the Rule of Two and Four as you play your drawing hands. It is a very valuable tool indeed.