Quote:
Originally Posted by TheShakeDaddy
How do you quickly calculate EV while in a hand. Also, when and how do you use EV. Examples?
Thanks
EV is a tool used by economist and gamblers alike to determine the value of an action if you were to perform the exact same action a larger number of times. This is done creating a weighted sum of the outcomes, and then subtracting the cost.
For example, if I have a 10 sided dice, it costs me $1 to roll the dice, and I get paid $11 if I roll a 10, then I calculate EV as follows
EV=(the sum of Probability of an Outcome*The value of the outcome)-cost of the action
So
EV=(10%*$11)+(90%*$0)-($1). EV in this game is $.1. If you do this game a million times, you will average a net value of $.1 per bet.
Anytime EV is positive, it is a good action to take. If it is negative, it is a losing action
to calculate EV, you have to create an outcome tree, and determine the liklihood and value of each outcome. This can be exceedingly diffcicult in poker when there are subsequent rounds of betting and stacks are deep.
For example, let's say I call a preflop raise of 3BB from the big blind with QTo. The flop comes KJ3r. I check, and the villain bets 5 BB. If I call, you have the following outcomes
1. I make my straight, and can get more action from villain
2. I make my straight, but villain shuts down
3. I don't make my straight on the turn, but villain doe not bet
4. I don't make my straight, and villain bet
5. I don't make my straight on turn or river, and I win at showdown
6. I don't make my straight on turn or river, and i lose at showdown.
And there are obviously a lot of other branches from the outcome tree that can occur on the turn and river.
This becomes almost impossible to calculate on the fly. What I will do is simplify and act is if I am playing with one card to go. I look at the value of the call, the likelihood of making my hand and how much I win and the likelihood of missing my hand. If I am looking to make a bet, I will also look at the likelihood of the villain folding (keeping in mind the amount you win if the villain folds is less than if he calls and you make your hand)
To estimate EV accurately, you need to be able to range your opponent, estimate how likely it is that he folds in certain situations, and estimate your likelihood of hitting certain hands. I usually practice this when I am driving out to the casino, and also practice this a ton using an equity calculator and Excel.
Note: my EV formula differs slightly from a lot of people. The use the formula
EV=(probability you will win*the pot you will win not including your call\bet)-(probability you will lose*the amount of the call\bet). It amounts to the same, I just find it easier to visualize if you place all the action from a round into the pot.