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Math Behind Betting Odds

There’s no doubt about it, gambling can be a ton of fun, especially if you’re winning while playing your favorite casino games. You don’t have to understand the math behind it, sometimes just the thrill of playing the game is enough for some players. But, it is important to note that, when you have a fundamental understanding of how the probabilities work, it can take your game to a whole new level.

Interested in learning more? In the following article, we will detail gambling math basics so that you can understand the math behind betting odds and gambling.

The first thing that you have to understand is probability i.e. the chance that a certain event will happen in a given situation. This can be expressed as a percentage, fraction, or odds.  So, as you can tell all probabilities are numeric values. Also, they are always a number between 0 and 1.

If something has a probability of zero, that means it can never happen. For instance, if you roll a six-sided die, with numbers from 1 to 6, the probability of rolling a 10 is 0.

Alternatively, if something has a probability of one, it is sure to happen. For example, if you roll the same six-sided die mentioned above, the probability of rolling any number from 1 to 6 is is 1.

To calculate the probability of an outcome, take the total number of ways that it takes to achieve something and divide it by all the outcomes. For example, if you wanted to calculate the probability of landing on Tails when you flip a coin, the first thing you would do is consider the total number of ways it can land on tails. Since all coins have two sides, the probability of it landing on heads is one. Similarly, the total number of possible outcomes is two, which means the probability of it landing on tails is 1/2 or 50%.

Odds are simply another way of expressing a probability. But, in this instance, you will be looking at the number of the ways that an outcome doesn’t happen versus the number of ways that it can happen. For example, when you flip a coin the odds of getting heads are 1 to 1. If you are rolling a 6-sided die, your chances of getting one are 5 to 1.

Both probability and odds matter when you’re gambling because bets tend to pay off at certain odds. When the bets pays off at the same probability of winning, you have what is called an even money situation. In other words, you win 50% of the time. For example, if you bet $2 to win $2 on a coin flip, then you’re making an even odds bet. Over time, you will be expected to break even.

But, what happens when you bet $2 for the coin to land on heads and if you win you get $4? Over time, you will win a large amount of money because half the time you win $4 but when you lose you will only take a $2 loss.

Casinos make money off from the difference between the odds that they put on the bet and the odds that you actually win the bet. For example, when you bet $5 on black at the roulette table, you will win if it indeed lands on black, but you will lose if it lands on red or any of the green zeroes.

On an American roulette wheel, there are 38 possible results, 18 of which are black. So, the probability of winning a bet on black are 18/38 or a little bit over 40%. In other words, the casino will win a little bit more than half the time and this is how they make their profit. The higher the difference between your odds of winning and odds of that are actually paid out will determine how big the casino’s house edge actually is.

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