Roulette superstitions, like any other gambling superstitions, run rampant throughout the casinos. Most of these irrationalities stem from not understanding the idea of independent events. This page examines some of these common false beliefs about roulette and how an understanding of independent events can make you a smarter gambler.

The biggest myth in roulette is that the results of the previous spin have something to do with the results of the next spin. Most gamblers think that if the color black has come up seven times in a row, then betting on red is a good idea. The thought is that eight black spins in a row is unlikely.

It is true that it’s unlikely to get eight black (or red) results in a row. But that misses the point. When you place that bet on red after the first seven spins, you’re not betting on whether or not there are going to be eight blacks in a row. You’re betting on the result of a single spin. The results of the previous spins are irrelevant.

Each roulette spin is an independent event. The odds of any given result on any given spin are exactly the same. If you were able to make some kind of proposition bet related to the results of multiple spins, then previous spins would matter. But every spin and every wager means you’re starting all over again.

Using the example from the previous section, different gamblers might draw different conclusions. One person might think that since black has come up seven times in a row that it’s more likely to come up on the next spin because those numbers have become “hot”. They’re wrong, too.

You’ll encounter two types of roulette wheels:

- An American roulette wheel,
- A European roulette wheel

An American roulette wheel has 38 possible results. 18 of those possibilities are black, 18 of them are red, and 2 of them are green. (Those are the 0 and the 00.) A European roulette wheel only has 37 possible results, though, because they eliminate one of the green zeroes.

The probability of getting black (or red) on any given spin is easily calculated. To calculate the probability of any given event, you divide the number of ways you can get that event by the total of all possible events. In this case, you have 18 possible ways of getting a black result, and 37 (or 38, depending on which wheel you’re playing on) total possible events.

18/37 is the same as 48.65%. 18/38 is the same as 47.36%. So no matter which kind of roulette game you’re playing, your chances of winning an even-money wager is slightly less than 50%.

It doesn’t matter what the previous results look like. Each spin of the wheel is an independent event. The wheel has the same number of potential results regardless of what happened on the previous spin.

Some smarty-pants out there will probably point out the possibility of a “biased” roulette wheel. Since these wheels are mechanical in nature, and since all machines are less than perfect, it’s possible that a wheel might be more likely to hit certain results than the straight math might indicate.

The reality is that identifying a wheel with a bias is impractical in the extreme. You’d have to track the results of thousands of spins before you could be sure that the bias actually exists. And after all that work, there’s no guarantee that the wheel you’re tracking will turn out to have a strong enough bias to give you an edge if you knew about it. Besides that, casinos move roulette wheels and tables to different locations, so you’d never be able to take a break from watching, because sure enough, as soon as you do, that would be when the casino would be swapping out their roulette equipment.

You can bet on your date of birth if you want to. You can bet on your favorite number, too. In fact, you can come up with any kind of scheme to determine what your lucky number is. But the reality is that lucky numbers don’t exist. Luck is just another word for statistical deviation.

I suppose if you believe in lucky numbers, no amount of scientific or mathematical evidence is going to change your mind. The idea that the universe cares enough about your date of birth to ignore the laws of physics in order to give you a win is ludicrous, but if it makes you happy, more power to you.

Superstitious roulette players often raise or lower their bets based on how their night is going. They might have a system for this, like the Martingale system, which suggests doubling your bet after every loss until you have a winner. Others might just base their bet sizes on intuition or how well they’re doing.

For example, I have a credulous friend who believes that if he loses three even-money bets in a row that his luck has turned cold, and he should quit playing or lower his bet sizes. On the other hand, he thinks that if he’s won three even-money bets in a row, then his luck is running good, and he’ll raise his bets.

He’s not systematic about this, but he occasionally has winning sessions. Of course, everyone will see occasional winning sessions at the roulette table. That’s true of any casino game. If no one ever won, then no one would ever play, and the casinos would go out of business.

The casino has an insurmountable mathematical edge in every game, though. They will always, over the volume of bets that they take, win more money than they will lose. No amount of superstition, hocus pocus, or wishful thinking can change that. That doesn’t mean you shouldn’t play. If you think roulette is fun, then have fun playing.

Just don’t think that you’re going to become a winner based on some silly superstitions that ignore math and physics.