Roulette Odds and Probabilities

If you’ve ever felt intimidated by the strange rules and customs at an in-person casino, try online roulette! You don’t even have to get dressed up, and leave your car in the driveway. Just open up your laptop and you can start betting in minutes.

After you sign up for an online casino (and depending on the casino, downloaded the software) you can start playing immediately. You’ll probably find there are two types of roulette available — American and European — and plenty of available bets. Where to start?

American vs. European Roulette

The difference between an American and a European roulette game starts at the wheel. American wheels have the standard slots numbered 1-36 plus single 0 and double 0 (00) slots. European wheels only have the 1-36 slots and a single 0 slot.

From a betting perspective, you’re always better off playing on a European wheel. The “house edge” on an American wheel is 5.26% for all bets except the “first 5” (0-00-1-2-3) where it jumps to 7.89%.

On the other hand, a single-zero wheel gives the house an edge of just 2.70% — and that’s before taking into account better-friendly European rules like the “half back” / “La partage” or “en prison” rules.

roulette wheels

Placing Your Bets

Placing your bets is as simple as picking your betting limit and putting down your chips. Putting down your chips is usually just a matter of clicking the numbers you’d like to bet on.

After you place your bets, then the casino’s “virtual dealer” calls out “No More Bets,” and the roulette wheel will spin. Once it comes to a stop, the roulette ball will be resting in a certain slot and any winning bets will get paid out immediately.

Of course, there are many other places to bet on besides the numbers. Ordinary American or European roulette games let you bet on odd or even, red or black, and columns or sections. (Columns pay 2 to 1 — you get back your bet plus twice what you bet — and odd/even and red/black pay 1 to 1.)

What’s more, you can also bet on adjoining numbers (this is known as a “split”, it pays 17 to 1) and four numbers at a time (where you place your bets on the inside corner among four numbers, this pays 8 to 1).

The Odds

Almost any bet you choose will make you the same amount of money in the long run. Red, black, odd, even, 1 to 18, and 19 to 36 all have just over a 47% chance of winning (on an American table, the number is a bit higher on European wheels) and pay 1 to 1.

The probability of winning goes down as you bet on fewer numbers, but the payout goes up in turn. Therefore, placing your bet on just one number means there’s just a 2.63% chance you’ll win (on an American wheel)… but if you do, you’ll get a stunning 35 to 1 payout.

Over the long run, therefore, the house still keeps their 5.26% edge (or 2.7% on a European wheel). The exception, again, is betting on “first five,” where the payout is low for the chance of winning — with this bet, the “house’s edge” is 7.89% (on an American wheel).

If you want to read a bit about some of the unusual ‘systems’ that people, take a read of this article.

European Rules

Things are a little more complicated on a European wheel. However, the complication is in your favour! European wheels don’t just remove the “double zero” which gives the house an extra edge. European wheels also have a “half back” / “la partage” and/or “en prison” rule.

Under the “half back” or “la partage” rule, if you place an even money bet (such as odd, even, black, red, 1-18, or 19-36) but the ball lands in the zero slot, you get half your bet back!

The “en prison” rule means that you can also choose to “imprison” your bet if this happens. If you imprison your bet, it will remain until the next spin — at which point, if the bet wins, you’ll get your money back (without any winnings).

Some casinos will let you keep the bet imprisoned until it wins, at others it loses. However, statistically you’re generally best off losing half up front, because there’s always a risk the ball will land in 0 again.

Where To Play Roulette Online

Here’s a quick summary of the different casinos available. For a more detailed review you can take a look at this website which has plenty more info about online roulette.

888 is one of the oldest casinos, and one of the best regarded. They have webcams and microphones so you can communicate with live dealers — you don’t feel like you’re “playing against a robot.”

Bet365 is a UK-based casino with a huge variety (over 200) of games to choose from. Like 888, they offer live dealers, but only for some games (roulette, blackjack, casino hold ’em, and Sic Bo).

Jackpot City is another well-established casino with one of the largest game selections (over 450). It’s also repeatedly won the Best of Online Gaming award.

US players are not welcome at any of these three. For US-based players, Grand Parker or Bovada are your main options. Grand Parker has a smaller selection of games but a very “glitzy” design, while Bovada offers a wider variety of games.