How do you calculate the variance of a bet in poker?

Incog

Well-known member
$Points
1,884
In poker, variance is calculated by determining the standard deviation of the expected value of a bet. To calculate the standard deviation, you need to know the probability of winning and the payout for each possible hand. Once you have those numbers, you can use the following formula: Variance = ( Payout - 1 )2 * probability of winning This formula gives you the average amount by which your wins and losses will vary from the expected value.
 
To calculate the variance of a bet in poker, you need to follow a few steps. Let's break it down:

1. Determine all possible outcomes: Start by listing all the possible outcomes of the bet. In poker, this could include winning, losing, or tying with the opponent.

2. Assign probabilities to each outcome: Assign a probability to each possible outcome based on your knowledge and estimation. For example, if you believe you have a 70% chance of winning, assign a probability of 0.7 to the win outcome.

3. Determine the payout for each outcome: Calculate the payout or return for each outcome. This is the amount you would win or lose in each case. For example, if you win $100 or lose $50, the payout for winning would be $100, and the payout for losing would be -$50.

4. Calculate the expected value: Multiply each outcome's probability by its corresponding payout and sum them all up. This will give you the expected value, which represents the average outcome of the bet.

5. Calculate the variance: The variance measures the spread or deviation of possible outcomes from the expected value. To calculate it, subtract the expected value from each payout, square the result, multiply by the corresponding probability, and sum them all up.

Let's use a simplified example to illustrate the calculation:

Assume you have a 70% chance of winning with a payout of $100, and a 30% chance of losing with a payout of -$50.

Expected Value:
(0.7 * $100) + (0.3 * -$50) = $70 - $15 = $55

Variance:
((($100 - $55)^2) * 0.7) + (((-$50 - $55)^2) * 0.3) = (45^2 * 0.7) + (105^2 * 0.3) = 2835 + 3307.5 = 6142.5

So, the variance of this bet would be approximately 6142.5. This value represents the average amount by which your wins and losses will deviate from the expected value.

Keep in mind that this is a simplified example, and in real poker scenarios, calculating variance involves considering more complex factors such as the number of opponents, possible hand combinations, and additional betting rounds.
 
In poker, the variance of a bet is calculated using the following formula:
Variance = (Payout x Probability of win) - (Cost of bet x Probability of loss)
So, for example, let's say you make a $10 bet on a hand of Texas Hold'em, and the probability of winning is 20%. The payout for winning is $20. The probability of losing is 80%. So the variance would be:
Variance = (20 x 0.2) - (10 x 0.8)
Which gives us a variance of -$6. This means that on average, for every $10 bet, you would lose $6 in the long run. However, it's important to remember that variance is only an average, and it doesn't tell the whole story. You could have some big wins and some big losses, and your actual results could be quite different from the expected value.
 
Back
Top