Understanding Roulette Odds Probability

As you’ll probably already know, Roulette is one of the only casino games where you’re totally in the hands of fate. You can be the most-skilled player out there, but no matter how good you are, there’s no way of influencing the ball or the wheel!

Instead, being successful at roulette comes down to knowing your roulette odds inside out and making the right bets. Your average player will choose their favourite numbers or go for red or black, whereas your seasoned roulette expert will put their chips in the right places, understand side bets and maximise the odds on the layout to have fun and hopefully win big!

To help you get the most out of your game, we’ve collected all the roulette odds you need to know.

The Basics of Roulette Odds: Inside or Outside Bets

First things first: What are inside and outside bets? You’ll hear these terms at the roulette table, and they refer to the section of the table where you place your bets.

But should you choose inside or outside bets? Well, that’s completely down to your gameplay, your bankroll, and ultimately what you want to get out of your time at the table / playing roulette online.

Payouts on inside roulette bets

Inside bets see longer odds, as you’re essentially picking one number out of dozens in the hope that it comes in. Naturally, there’s the house edge (the zero) to consider, so the percentage chance of winning is slightly lower than the amount of numbers on the wheel.

Payouts on outside roulette bets

For certain outside bets, like colours, odds or evens, and lows / highs, you’ll get odds of 1:1, so you’ll double your bet if it comes in. But again, this is never a 50/50 bet – more like 48.65% chance, with the house edge coming into play.

However, if you select a combination, like choosing which set of dozen the ball will land in, putting your chip on sides or corners, or selecting lines / streets (rows), the potential payouts rise as the odds increase.

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Calculating roulette odds

The easiest way of calculating your odds is to know the payouts, the house edge, and the probability of your bet coming in. Although you can do the maths in your head (if you’re particularly good at maths), it’s much easier just to memorise the percentages and go from there.

We’ve collected all the odds for all types of table to make life easier!

A really important thing to remember in Roulette is that the odds never change. What does this mean?

A common mistake that players make is to assume that because a certain set of results have happened in a row, the next outcome has to be different. But it doesn’t matter if the ball lands on black 10 times in a row – the next spin gives you a just under 50/50 chance of it being red or black, regardless of previous results. You may have heard of this misconception being referred to as gambler’s fallacy.

Calculating the odds for consecutive numbers

This is where things get interesting. Can a ball land on the same number twice, three times, or an infinite number of times? Well, it’s entirely possible. As we’ve mentioned, every number on the wheel has the same probability, no matter what. So, if you were to bet on the same number over and over, you’d have the same odds of it coming in.

But stack those probabilities on top of each other, and they start to get long. Really long. If you work on a 1 in 37 chance for a European wheel, then the probability of the same number happening again goes to 1 in 37 to the power of two, which is 1 in 1,369. Then to the power of three. And so on until you run out of space on your calculator screen. But that’s only if you were to bet on that actually happening. In reality, you can only bet on the outcome of a single spin, so even if the ball landed on the same number 100 times, you’d only ever collect winnings at 35:1 each time.

Calculating the odds for streaks

Streaks refer to the outside bets coming in multiple times, and the same principle applies – you’re only ever going to be able to bet on a single spin of the wheel. So even though the probability of three blacks in a row appearing is higher, you’ll still only get a payout at the probability of it happening with each individual spin.

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Top tips for playing Roulette

Choose European Roulette

With only one zero, European Roulette significantly reduces the house edge of the Roulette wheel. This means that the odds will be ever so slightly in your favour, which could make a big difference. If you’re just going to pick your favourite number for a few spins, then you don’t need to worry too much, but if you’re going to apply your roulette odds knowledge, then the wheel with one green is the one!

Play Outside Bets

Although super-exciting if the ball lands on your lucky number, you won’t win as often as if you choose outside bets. Although you’ll get a lower payout, you could build a nice pot.

Don’t Chase Losses

Like any casino game, trying to win back money you’ve lost isn’t a good strategy. Gambling means you can lose and stacking up another loss on top of a loss can be problematic. Instead, decide on your initial budget, make sure you can afford to lose that amount, and stop playing once it’s gone. If you end up winning more than you started with, then great, but Roulette is about having fun, not trying to earn money.

Have fun and know when to stop

And with that, if the game stops being fun, or you’ve used up your bankroll, then log off and try your luck next time. If you struggle to disconnect from gambling, or find yourself gambling more often, then check out Be Gamble Aware for support and advice. And remember, we’ve got a wide range of handy tools available to help keep things fun.

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Roulette Odds Probability FAQs

Does probability work in roulette?

Roulette is all about probability – you’ll see that in the pay table on the layout when you first enter a game. The trick is using probability in your favour, and not falling for the typical fallacies like waiting to bet black after four reds in a row. The probability never changes, which you can aim to predict!

How can I improve my odds of winning at roulette?

You’ll never improve your odds of winning – the odds will always be the same no matter what.

Is it possible to calculate the exact probability of winning a particular bet in roulette?

Yes, and often you won’t even need to do it yourself. All roulette games have a pay table that will include odds and probabilities, including the house edge, so you’ll know exactly what the outcomes could be before you bet a single chip.

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Fancy putting your new-found knowledge of Roulette odds to the test? We’ve got dozens of roulette tables at William Hill Vegas. Remember to keep an eye for those welcome bonuses if you’re a new player too!