Major Poker mistakes  continued...

If you see your opponents’ hands and knew exactly what everyone was holding, you could easily determine the likelihood that you would win using mathematical probabilities.

But the reality is that you rarely know for sure what you opponents have drawn preflop, so you will have to rely on player reads to make a best guess as to the strength of other players’ hands.

How can you do this? 

First you should deduce a series of possible card combinations that you suspect your opponents to hold. 

Next, you can compute the likelihood that you will win the hand based on each of these suspected preflop combinations. 

Finally, you will take an average of the probability that you will win the hand, given each of the individual outcomes. This is the expected value of the hand.

Example:
Your hand: The flop: 

Based on player reads, you determine that your opponent has one of the two following hands:

Outcome A: Outcome B: 

To determine the expected value of you winning the hand, you need to determine the probability that your hand would beat out your opponent if his preflop is Outcome A, and the probability that you would win if his hand is Outcome B.

In this case, a probability calculator would tell you that you stand a 13% chance of winning against Outcome A and a 53% chance of winning against outcome B. The average of these two outcomes (the sum of 13% and 53% divided by 2) is 33%.

 Therefore you have a 33% chance of winning this hand if you don’t know which of these Outcomes is more likely.

But you can see that if you were able to determine that your opponent most likely had one outcome or another, it would affect the expected value. 

Say, for example, that you are 85% sure that your opponent has Outcome A: the Ace and Kings of Clubs. There is only a 15% chance that he, instead, has the Jack and King of Hearts (Outcome B). In this case, the expected value would be just 19% (EV = .85 (13) + .15 (53)). You would be less likely to bet high on the hand now that you realize you have a smaller chance of winning.

This example illustrates how it is to your advantage to narrow down the outcomes as best you can, so as to get an accurate an expected value as possible. 

As a final consideration, you need to look at the pot size in order to determine if you will be making a small mistake or a big mistake by making a certain decision. 

Knowing the pot odds is critical to making any betting decision, and can actually be a shortcut to evaluating whether or not to bet. As a rule, if your opponent is betting considering more than the size of the pot, you need to high chance of winning the hand to justify betting. 

Example 1:

The pot is $20 and your opponent makes a bet of $40. The pot is smaller than the bet in this case – in fact, the bet is two times the current size of the pot. The probability that you will win the hand will need to be considerably high in order to justify meeting this bet, since the expected value of the hand will need to be greater than $40 (the bid you are contemplating). 

If you calculate that you have a 20% of winning the hand, should you make the bet? 

Pot odds = (Pot + Bid) * Probability of winning 
If pot odds >= bet, then you should place the bet

In this case: ($20 + $40) * .2 = $12
Since $12 is less than the $20 bet, you should not meet the bet.

Example 2:

What if the pot is $400 and your opponent makes a bet of $40. The bet is just 10% of the pot in this case. Should you make the bet in this case?

Pot odds = (Pot + Bid) * Probability of winning 
If pot odds >= bet, then you should place the bet

In this case: ($400 + $40) * .2 = $88
Since $88 is over four times the $20 bet, you would do well to place this bet.

Next: Evaluating Texas Holdem  hand values like a Pro