Short Stack Strategy: Advanced Preflop Play
Introduction
In this article Equity over charts
 Limping and completing
 Squeeze play
You've probably got used to it by now: you're dealt a playable hand but can't find it in the chart. So far you have learned to automatically fold these hands. This article will address whether this is always the right decision, or if you can make exceptions and play hands that aren't in the chart.
You will learn when to limp in and when you should raise with hands not found in the chart. You will also learn the basics of squeeze play.
Video: Advanced Short Stack Strategy: Preflop Equity 

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In this video our SSS coach Xarry2 talks about preflop equity. This video is highly recommended for players wanting to advance their knowledge of preflop play past the stage of the Starting Hands Chart. Watch the video "Preflop Equity" by Xarry2 
Playing for equity
What is equity? Equity, or pot equity, refers to the share of the pot belonging to a player based on his long term chances to win. 
Equity is the real key to successful preflop play. Pay close attention to this section of the article. The following example should help you understand the concept of equity better.
Example:
You have AK and are facing two opponents, who each have two random cards. What is your equity?
The Equilator shows your equity is approximately 48%. Now assume you make a standard 4BB raise and both players (no matter what cards they have) call. How many BBs will you win on average?
There are now 12 BBs in the pot. You have 48% equity, which means 5.76 BBs belong to you. Every time you raise, you make a profit of: 5.76 BBs  4 BBs = 1.76 BBs.
Of course the hand isn't over yet, but you will make even more profit if you play well after the flop.
Put yourself in the following situation: You have JJ and an opponent raises from an early position. The chart says reraise and you go allin.
You can risk your stack with JJ against opponents known for their loose raises, but is it the right decision against other opponents?
Raising an average player with JJ is certainly correct, but some opponents' ranges are so tight, that you won't be a favourite with JJ.
The next section will show you when to go allin and how to determine your equity. As in the past, this article will require Elephant statistics, as well as knowledge and notes about your opponent.
Stick to the chart if he is an unknown. If not, you can determine when it would be profitable to reraise, based on his raise range and your equity.
$100 NL Hold'em
Stacks Hero ($20)
Preflop: Hero is Button with T T
UTG raises to $4.00, 4 folds, Hero ???
 A) UTG: 10/5 (VPIP/ PFR in UTG)
 B) UTG: 20/10
Your opponent's range in Example A is roughly: TT+, AQs+, AQo+. Using the Equilator you see that with TT you have 40% equity against that range.
Your opponent's range is much larger in Example B: 77+, A9s+, KTs+, AJo+ and KQo. Your equity against that range is appr. 53%. You and the raiser are the only players left in the pot, meaning you each pay 50% of the total pot.
You would need at least 50% pot equity to play this hand. With 3 players in the pot you need 33%, with 4 players 25%, etc. This formula will play a key role in future decisions, because you can now respond to each opponent individually.
This rule of thumb doesn't apply to every single situation though. Your opponent won't call a reraise with every raise. The final formula is a bit more complicated. First of all, you need to determine the percentage of calls he makes in his raise range. Then you work out the chances that he will fold to your raise. The sum gives you your exact EV:
FE = Fold equity
Pot_{1} = Pot size before your reraise
Pot_{2} = Total pot size if your opponent calls
Equity = Your chances of winning against his calling range
Costs = Size of your reraise
EV = FE * Pot_{1} + (1FE) * (Equity * Pot_{2}  Costs)
This is however not the only formula you need for poker. Fold equity also plays an important role. A reraise can be +EV even if you theoretically have less than 50% equity, provided your opponent folds often enough.
The beginner section gave you a range for going allin in response to a raise. Following the chart would have you making the right decisions on average, but the fact is that each opponent plays differently. Folding TT to a raise is the right decision against some players, whereas you would be losing value doing so against others.
Stats allow you to respond to each opponent individually and to adapt your allin range accordingly. The important thing is having information on your opponent. You won't be able to play based on equity without stats. The following example will show you how to make the right decision.
$100 NL Hold'em
Stacks Hero ($20)
Preflop: Hero is MP2 with 9 9
4 folds, Hero raises to $4.00, 3 folds, SB raises to $20.00, BB folds, Hero ???
Here are your stats on the SB:
 A) SB: 15/10/5 (VPIP / PFR / 3Bet)
 B) SB: 20/15/10
VPIP shows how often that player voluntarily invests in the pot. PFR shows how often he raises before the flop, and 3bet shows how often he raises when exactly one raise was made ahead of him. This is also the stat required to make a decision in this example. Use the Equilator to determine your equity against your opponent's range.
Example A: Your opponent's 3bet range is 5%, which would roughly consist of TT+, AQs+, AQo+. We see that we have app. 37% equity against this range with pocket nines. Is that enough to call?
The first thing you have to know is how much equity you need. Is the answer 50% because you are investing 50% of what goes into the pot? The answer is no. In fact, you need less. Reason: you've already invested money into the pot, so this money in the pot isn't yours any longer.
You have to calculate your pot odds to determine the equity needed to call. To do so you take the amount already in the pot and add the SB's raise.
Pot Odds 1:1.56 ($24 in the pot + $16 you must pay)
You can convert the odds to equity by adding both figures and dividing 100 by that number. For example: 1 + 1.56 = 2.56, 100 / 2,56 = 39. Your equity is therefore 39%.
This means you can call when you have at least 39% equity on your opponent's range. You have to fold this time, since you only have 37% and would lose money in the long run by calling.
Example B: Once again the pot odds are 1:1.56 and you need 39% equity to call. This time, however, your opponent's 3bet range is at 10%, meaning anything from 77+, A9s+, KTs+, AJo+ to KQo. You have 48% equity against this range and can call his bet based on odds.
Make your own examples with other starting hands and opponent ranges, to practice using this formula.
Remember that opponents' ranges can differ from those produced by the Equilator. If you know this to be the case you have to make the right adjustments. Your opponent in Example B could, for example, have 66 instead of A9s. It's pretty impossible to calculate an exact range, which means you have to estimate.
 1. Calculate the pot odds
 2. Determine your opponent's range
 3. Calculate your hand's equity against your opponent's range.
 4. Call when you have +EV.
#1 WildBeans, 02 Mar 09 04:21
I don't understand this calculation:<br /> Quote:<br /> You can convert the odds to equity by adding both figures and dividing by 100. Take a look: 1 + 1.5 = 2.5, 2.5 / 100 = 0.4. Your equity is therefore 40%.#2 SoyCD, 02 Mar 09 16:29
@1: Sorry was a mistake in the translation. If you add the two numbers and divide 100 by them you get your equity. So 1+1.5 = 2.5 and 100/2.5 = 40 (% Equity).<br /> <br /> You could also divide 1 by whatever the sum of the two numbers is to receive the Equity in actually percentage form so 1/2.5 = 0.40 so 40% <br /> <br /> :)#3 delete461, 19 Dec 09 07:02
Quote:<br /> Your opponent's 3bet range is 5%, which would roughly consist of TT+, AQs+, AQo+. We see that we have app. 37% equity against this range with pocket nines. Is that enough to call? <br /> <br /> Actually equilator says we have 43% equity with 99 against a 5% range, making a call profitable.#4 asmirovic, 16 Sep 10 11:33
Where you draw out FE of oponent? <br /> Thx#5 DominiqueRoyal, 14 Mar 11 22:47
how do I know what stats have my oppenents, 3 bets? I nned to use poker tracker or what ?#6 DominiqueRoyal, 14 Mar 11 22:50
where do I Get opponent stats ? and I dont get how to get opponennts range, I mean how to calculate equity#7 David, 15 Mar 11 07:42
@6: For opponents stats you´ll need dedicated Software like f.e. Pokerstrategy.com Elephant:<br /> <br /> http://www.pokerstrategy.com/software/9/