Ways Roulette Players Can Use Math to Win

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Roulette is a simple game that has very little to do with a spinning wheel and ivory ball. Instead, it’s a game based on the simple math of a set number of spaces and the odds of the final number landing in a spot where you win.

The math used in roulette is easy to understand and use once you learn how to look at it. This article includes six ways you can use math when you play roulette to help you win.

The Math That Makes Roulette Work

While most gamblers look at real money roulette and think the game is based on an ivory ball spinning around a wheel, the truth is that the ball and the wheel don’t really have anything to do with the important part of the game. The important part of roulette is how many spaces are available.

Roulette games almost all have either 38 spaces or 37 spaces. And the odds of winning any wager you make are directly influenced by the total number of spaces that are available.

For Example:

If you bet on an even money bet like black, you win on 18 spaces. On a wheel with 38 spaces, you win on 18 spaces and lose on 20 spaces. On a wheel with 37 spaces, you win on 18 spaces and lose on 19 spaces.

The amount you win is the same on both wheels, but you have a better chance to win on a wheel with 37 spaces. This is true for every wager you can make playing roulette.

A casino could use a random number generating computer set to 37 or 38 numbers instead of a roulette wheel and a ball and offer the exact same game and odds.  Look at the odds of winning every bet on the roulette wheel to learn more about how this works.

Double Zero Roulette Math

The most common roulette tables and wheels have both a double 0 and single 0 space. These tables are also called American Roulette tables. American Roulette tables aren’t very good for gamblers. You have many other options in the casino that offer better odds.

All of the wager options on an American Roulette table have the same return percentage except for the basket wager. And the basket wager has a lower return than the other bet.

Here’s how to determine the return percentage. When you bet on a single number, you win 35 to 1 when you win. But you only win 1 out of 38 times. If you bet $10 38 times and win once, you risk $380 and only get back $360.

Divide $360 by $380 and you see the return is 94.74%. You can run the same numbers on other bets like even money wagers.

It costs the same $380 to make 38 $10 wagers, and you win 18 of them. The total return on 18 wins is the same $360, creating the same return percentage.

Nothing you do changes these numbers. These are mathematical facts about roulette.

European Roulette Math

Now you know how to determine the return percentage on a roulette table. European Roulette tables and wheels offer the same pay outs as American Roulette, but there are only 37 number spaces. Here are the same examples used in the last section with a European Roulette table.

You bet $10 37 times on a single number. Your total cost to make 37 wagers is $370. You win 1 out of the 37 times and get your $10 wager back plus the $350 win, for a total of $360. Divide $360 by $370 and you see the return is 97.3%.

When you bet on an even money wager 37 times, you risk the same $370. You win 18 times, receiving your wager of $10 back and a win of $10. This is a total return of $360, creating the same return to player number.

Just to prove that it doesn’t matter what you bet on, here’s an example on a two-number wager. A two-number wager, like on 2 and 3, pays 17 to 1. 37 wagers is a total cost of $370. You win 2 out of 37 times, and when you win, you get back $10 plus $170. This is a total on the two wins of $360, just like the other examples.

French Roulette Math

French Roulette and European Roulette are almost exactly the same game. They use the same 37 number table and wheel, and most of the rules are the same. But French Roulette has one special rule that makes it a much better option.

The Special Rule:

Is when you bet on an even money space and lose, your loss is placed in prison. If you lose the next even money wager, you lose the bet that’s in prison. But when you win the next even money wager, the money in prison is returned to you.

This cuts the edge the casino has in half when compared to European Roulette tables. What this means is that if you play roulette, the only option you should ever consider is making even money wagers on a French Roulette table that uses the in prison rule.

You need to verify the rules before you play. Some casinos call their roulette French Roulette but still use the European rules. Simply ask if the table uses in prison roulette rules. This is also called “en prison” in some places.

Other Roulette Variations

I’ve seen a few different roulette variations that aren’t discussed in other sections on this page. All of these different variations have one thing in common. They’re all terrible. This means that you should simply never play a different variation of roulette.

While it’s not common, the main variation I’ve seen has three spaces with zeros. So, instead of having 37 or 38 spaces, the table and wheel has 39 spaces. You can understand why this is bad by using the same math that you saw in previous sections.

Which is better—1 in 37, 1 in 38, or 1 in 39?

The answer is clearly 1 in 37. On a single spin this might not seem like a big difference. But over the course of 100’s or 1,000’s of spins it makes a big difference.

I’ve also seen something like a mini roulette game that has fewer total spaces. These games might look better but the odds are still worse than French Roulette in every case that I’ve seen. The standard in the casino industry is that if the casino offers a variation of a traditional game, it’s almost always worse than the original game for gamblers.

Are Roulette Bonuses Good or Bad?

Online and mobile roulette gamblers can find casinos that offer bonuses. Roulette bonuses are a good option if you want a bigger bankroll, but they’re not usually useful in any way to help you win. The main reason for this is because if you play roulette long enough the casino is going to win.

This is because even the best roulette games still give the casino a small edge. And a small edge is all the casino needs to take your money if you play long enough. And this leads to the second issue with roulette bonuses.

Mobile and online roulette bonuses come with specific terms and conditions when you accept them. You might double your bankroll, but you agree to risk a certain amount of money before you can get your money out of the casino.

The amount you have to risk is usually high enough that the casino has time to let their edge take your money as profit. This doesn’t always mean that you should avoid roulette bonuses, but it does mean that you need to be careful with them. You might be signing up for something that you don’t need or want in the long run.


Roulette odds are based on how many spaces are on the wheel. Roulette results don’t have anything to do with balls and wheels. The results are random and can be reached using other forms of random number generation.

The best roulette games are the ones that have the fewest number of spaces. A game with 37 spaces is far superior to a game with 38 or more spaces. This is really all you need to know when it comes to strategy for roulette.

Finally, you can use online roulette bonuses to start with a bigger bankroll, but the math shows that most of these roulette bonuses aren’t going to help you win.

Michael Stevens

Michael Stevens has been researching and writing topics involving the gambling industry for well over a decade now and is considered an expert on all things casino and sports betting. Michael has been writing for GamblingSites.org since early 2016. ...

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