Counting Outs in Hold'em
In poker, calculating your outs and chances of winning the pot is fundamental to beating no limit hold'em games, a form of the game where the pots can get big really quickly. Although it can seem like a complicated subject to grasp at first, you really don't need a mathematical mind to have a command on it.
Put simply, if you expect an opponent has the best hand, you know you need certain cards in the deck to improve your hand. The cards that you need to make the best hand are referred to as your “outs”. If you know how many cards or “outs” are needed, you can more accurately calculate the equity and chances of winning the pot during any stage of the hand.
With this information you can instantly figure out whether or not you're getting good pot odds to call even with a weak made hand, because if you get certain cards on the next street or by the river, there is a good chance of stacking your opponent.
Because it's easier calculating hand equity on the spot as a percentage, it's good to convert the ratio of pot odds as a percentage to more easily compare the two and determine if you should make the call.
The most basic principle is the hand equity, which is determined by calculating your outs must be greater then the pot odds you're getting. If the equity is greater the play is going to make money in the long term and drawing to the best hand is likely worth pursuing. If your hand equity is the exactly the same as the pot odds then it would be a break even play, which means it won't make money or lose money in the long term. The important take home point is that you never want to call when your hand equity is less then the pot equity, since this will cost you money in the long run.
Calculating your hand equity requires you to count up how many outs are needed to make the best hand during any point of a hand. You can calculate your equity for the next card or you can calculate the equity if you get to the river. Usually it's a good idea to calculate hand equity for the next card because you can expect most opponents to keep betting on the next street. Although if it's an all-in situation then that's a moot point.
So, for example, you have an open-ended straight draw with 8 outs to hit the straight. If you know you have 8 outs on the flop with 2 cards to come you calculate your equity and chances of winning like this: (8 (outs) x 2 x 2= 32%.
The decision of whether to call or fold is usually a straightforward one on the flop. If you have a decent draw you are usually always calling because even if you are not getting exactly the correct pot odds to make the call, once you factor in implied odds in the future round of betting, you're easily getting good enough odds to call. The decision of whether to draw to the best hand is usually a tougher one on the turn. As an example, if you know you have 8 outs on the turn with only 1 card to come you calculate your equity and chances of winning like this: (8 (outs) x 2 = 16%.
Generally you should be letting go of weaker draws on the turn with the exception that it's a really big pot and an opponent has only bet a small amount, giving you good pot odds to call. But even in this situation you have to fear your opponent is chasing a better draw.
A common scenario is when you pickup more equity with a combo draw on the turn such as a pair and open ended straight draw (OESD). If you can expect making two pair to make the best hand, then you know you have 8 outs with the OESD and an additional 5 outs if you hit one of your 5 cards to make trips or two pair, so you have 13 outs in total.
Using the same hand equity formula, we know with 13 outs and just the river card to come we will have a 26% (13 x 2) chance of making the best hand. If you're facing a ½ pot bet you'd getting roughly 3:1 odds and you would need to have a 25% chance of winning, which you're getting without even contemplating implied odds, so you should make the call. It really is that simple.
Finally, when you're calculating your outs that you don't count duplicate odds. Say, for example, you're trying to hit a flush, but one of the flush cards is the same as other cards you can hit to make the best hand, then you want to avoid counting the same outs twice.