How to Determine the Odds of a Casino Game

A pair of black and gold dice rolling against a black background

If you know how to play casino games, odds are you’re aware of the importance of odds. They’re the numbers that indicate how much of a risk you’re running when placing bets on casino table games and slots, and they also determine how much of a payout you’ll receive should you be fortunate enough to win. The more you learn about odds, the better you’ll understand how they can inform your betting decisions. Whether you’re table-side at a land-based casino or curled up on the couch playing online casino games on your mobile phone, your betting strategy is sure to improve if you have a method of determining the odds. Let’s take a closer look at how it’s done.

The logic of odds

First things first. Let’s define what odds are. Odds are numbers used to measure the likelihood of a particular outcome, positive or negative, taking place. By comparing the number of favorable outcomes in a specific situation to the number of unfavorable outcomes, you can make a more informed prediction, or bet. If you roll a six-sided die, for instance, your chance of rolling a specific number is always 5:1. Every time you roll the die, your chance resets. It’s more complicated when you apply this logic to casino table games, but the same basic principle applies. You’re never guaranteed a win, but weighing up the odds helps you make more informed decisions.

Odds and payouts

Odds represent the probability of an outcome occurring divided by the probability of it not occurring. They also tell you what you’ll be paid out if you win your bet. The most common way of expressing this in numbers is fractional odds, written with a slash (/) or a hyphen (-). As an example, if you bet on an event with odds of 8/1 (eight-to-one), you’ll win $8 against every $1, plus your wager back. In this example of 8/1 odds for a $1 wager, you’ll win a total of $9. If, on the other hand, the odds are 1/8, you’ll need to bet $8 to win $1 and recoup your initial bet. It’s clear that the less potentially lucrative bet is safer than the other, although even safe bets are never 100% guaranteed. (Note that true odds, as described above, can differ slightly from payouts in online casinos in the USA.)

Roulette odds

Closeup of a casino Roulette wheel

If you’re looking to learn about odds, roulette is one of the best casino games to practice on. Take the example of French roulette. The wheel is divided up into 37 colored and numbered pockets where the ball can land. If you place a bet on the 0 or on any other single number (also known as a straight bet), there are 36 ways you can lose and only one way you can win, for odds of 36/1 – not great odds at all. But if you bet that the ball will land on any odd, even, red, or black number, the odds are 18/19, or nearly 1/1. This makes French roulette one of the casino games with the best odds of winning something. Between these two extremes, there are multiple different potential winning combinations, all with different odds. The quickest way to gain insight is to consult a roulette bet odds table. If you do, you’ll notice that American roulette has slightly different odds, less favorable to the player. That’s because American roulette has an extra zero space, so a straight bet, for example, will have odds of 37/1.

Blackjack odds

Working out the odds of card-based games is more difficult than with roulette. Roulette has a fixed number of winning possibilities every time you play, but the odds of winning card games change as cards are removed from play. Take blackjack, for example. It’s widely regarded as one of the best casino games with the lowest house edge in a land-based or live casino online setting. At the same time, the math behind the game is too complex for the majority of players to work out odds on the fly. That’s why experienced blackjack players repeatedly say that the only way to progress in blackjack is to learn basic blackjack strategy. With practice, you’ll gain insight into why your chances of busting are better with some hands than with others. As a rule of thumb, the higher your hand value, the greater your chances of going bust. If you have a 10 and 2, for example, your odds of busting are 30/1, increasing to 37/1 for a 10 and a 3. With Q and a 5, you’re at 53/1, and a K and a 6 push the odds against you to 61/1.


When it comes to poker, the key to figuring out your chances is the number of “outs”, which are the cards remaining in the deck that can improve your hand. That’s what the percentages you see displayed in televised poker games are based on. Let’s say the board is J♠ 2♠ 7♦ A♦ and you’re holding Q♠ and 9♠, so you’re looking to complete a flush. To calculate your chances of doing so, you subtract the number of spades in your hand and on the table (4) from the number of cards in any suit (13), for a total of 9 outs.

The next step is to subtract the number of cards in your hand (2) and the number of community cards dealt so far (4) from the deck total (52). That gives you 46. Now subtract your outs (9) from that number. That gives you 37 cards that will cause you to lose if they’re the last to come out. This gives you 37:9 odds of getting the win in this situation, which you can simplify to 4:1.

For a quicker method of calculating approximate poker odds, work out how many outs are left in the deck after the flop. Multiply this number by four to calculate the chance of a winning card turning up on the turn or the river. After the turn, multiply your outs by two for your winning chances on the river.

Slot machine odds

Closeup of a classic slot machine featuring BAR symbols

Unlike mechanical and card-based live dealer games such as poker, blackjack, and roulette, the outcomes of online slots are determined by random number generators (RNGs). Every time you press “spin”, a sophisticated algorithm kicks in to ensure a random result on the reels. There’s no way you could ever calculate the odds of an individual spin yielding a winning outcome. What you can do is work out the house edge. If you look at the paytable menu or rules screen of a specific game, you’ll typically find an RTP (return to player percentage). Sugar Surge, for example, has an RTP of 94.27%. Subtract this number from 100 for the house edge – 5.73% in this case. This means that on average, over time, you should get $9.43 (rounded from $9.427) for every $10 you wager. Don’t expect the game to return this percentage every time, though – wins and losses are random.

Enjoy fair odds at Borgata Online

Whatever your game, you can count on getting the best odds when you register to play casino games at Borgata Online. That’s because we’re committed to providing a recreational experience that’s safe, fair, and transparent. The rules and risks of our casino table games and online slots are available at all times, so you’ll always know what to expect. If you’re ever in need of answers or assistance, please consult our FAQs or reach out to our help desk 24/7.