Understanding Poker Odds and Outs
Every one knows that if you have a drawing hand, it is important to figure out the pot odds before you make a call. What that means is are the odds of you making the hand and winning the pot greater than the amount you have to call relative to the pot. Clearly it is hard to figure out the exact percentages in the middle of a hand when you only have twenty seconds to act. However there is a rule of thumb that will get you the correct odds within a percent or two and takes only seconds to learn and remember.
The first thing that you do is count up the number of outs that you have. Then the percent chance that the next card will be one of your outs is your number of outs multiplied by two. Say you are drawing to a spade flush. There are two spades on the board, two in your hand, which leaves nine remaining in the deck. Multiply 9 * 2 = 18 percent that the next card will be a spade.
Let’s examine this a little more closely. After the flop there are 47 unknown cards left in the deck, after the turn there are 46 which means that the odds of any given card being the next one to come out are
1/47 = 2.1 %
1/46 = 2.2 %
If we approximate this as 1 in 50 instead of 1 in 47 we see that any given card has a 2% chance of coming out. Which means to find the chance that one of our outs is next we simply multiply it by two. To find the chance that one of our outs comes on the turn or the river multiply it by four.
It is important to note that these are underestimates. i.e. this rule of thumb would approximate the chances of your flush coming to be 36 % instead of 38%. If you would like to be more exact, multiply by 2 or 4 and add 1 percent for every 8 chances you have of hitting your out. So in this case we would add 2% because we have 9 chances on the turn and 9 chances on the river for 18 chances total.