The Science Behind Betting Odds

The Science Behind Betting Odds
Reading time: 8 minutes

Do you feel overwhelmed trying to read or interpret betting odds when all you want to do is bet on your favourite sporting team? Our expert team is here to help. Think of us as your betting buddies, here to steer you through the odds labyrinth. This ain’t a math exam, folks!

We’ve put together a guide that outlines all of our expert advice, breaking down betting odds into bite-sized, easy-to-digest pieces. Even if numbers aren’t your jam, you’re covered! From the nitty-gritty of odds to using a betting odds calculator, we’ve got your back. So buckle up, and let’s roll into your next winning bet!

Let’s dive in!-

The Basic: What Are Betting Odds?

Betting odds are the bedrock of the gambling world, acting as indicators of an event’s likelihood and potential returns.

When you start running in casino circles, you will most likely run into the 3 main types of odds. These are decimal odds, fractional odds, or American odds aka moneyline odds. Regardless of the type (which we will dive into later) all of these figures are just fancy ways of representing the probability of an outcome.

For instance, fractional odds of 5/1 imply a lower chance of success than odds of 1/5.

Are you with me so far? Good!

What Is Probability?

When you begin learning about odds, you have to make sure you have a rock-solid understanding of the concept of probability.

Imagine probability is like looking at the weather forecast. When you see a weather report, you get a sense of what might happen – sunny or rainy. Similarly, probability helps predict the chances of a win or a loss in gambling.

Knowing a game’s implied probability helps players make informed decisions, and ultimately has a huge impact on potential winnings.

Implied Odds Vs. True Odds

Implied Odds

Implied odds are your personal estimation of the actual likelihood of an event occurring based on other factors.

For instance, in games like blackjack or poker, a player may consider the probability of their hand winning against the odds implied by the dealer’s visible cards or betting patterns. Implied odds involve assessing the chances of a successful outcome, based on the information available.

Understanding and distinguishing between ‘implied odds’ and ‘true odds’ is a game-changer for our cunning cardsharks.

True Odds

True odds in casino games represent the authentic chance of an event occurring during gameplay, like drawing a specific card in poker or hitting a particular number in roulette. These odds reflect the game’s intrinsic probability, showing the unaltered likelihood of a result.

For example, in dice games, the true odds of rolling a 6 on a standard six-sided die are 1 in 6. Recognizing true odds assists players in evaluating game fairness and making well-informed betting choices, especially when contrasting them with casino-provided odds.


Why Are Odds Important?

Odds play a crucial role in online casinos as they determine the likelihood of an event occurring in a game and the potential payouts for players. Here’s why odds are important for both casinos and players:


Understanding the odds helps ensure fairness in games. For casinos, providing transparent and fair odds is vital for building trust and maintaining their reputation. Players also seek games with fair odds to feel confident in the integrity of the casino.

Strategic Decision-Making:

Players use odds to make informed betting decisions. It allows them to strategize by assessing the likelihood of a specific outcome, guiding how much they’re willing to wager and the potential returns.

House Edge:

Casinos rely on odds to create the house edge, ensuring they have a slight advantage over players. This edge enables casinos to generate revenue over the long term, essential for their sustainability.

Insider Insight: Online Casinos do not have the same odds as land-based casinos – they are better! Typically, online casinos offer better odds due to lower operational costs. Classic games like Blackjack often have reduced house edges compared to land-based casinos.


Odds determine the payout structure. Players are attracted to games offering higher odds because it means better potential payouts for successful bets.

In essence, odds impact the fairness of games, influence player strategies, and shape the financial structure of both casinos and players’ bets. Understanding and leveraging odds effectively can make a substantial difference in the gambling experience.

How Are Betting Odds Calculated?

When you see numbers that are separated by a slash such as 10/1, this is a fractional odd. You can use this to calculate the probability of an event with this simple mathematical equation:

(%) = B / (A+B).

Let’s use 9/1 in replace of A/B.

9/1 can be calculated as 1 / (9 + 1) = 0.10 – There is a 10% chance of the event happening.

Reading odds to Determine your potential Winnings

So, here’s the deal! Once you get the hang of guessing how likely something is to happen, you can use betting odds to figure out how much you could win if you bet on it.

Let’s talk about fractional odds; they tell you how much you might win compared to your bet. For example, say you wager 1 NZD on a 4/1 chance. If you win, you’ll get back 5 NZD (4 NZD profit plus your initial 1 NZD stake).

Odds where the first number is higher are called “odds against,” and when the first number is lower, it’s “odds on.” Odds-on means bookies think it’s more likely, and odds against mean they’re not so sure it’ll happen. That’s the betting odds nutshell!

Types of Betting Odds

Fractional Odds

Fractional odds are written as 10/1, 5/2, etc. and with them, you can easily calculate how much you stand to win: if you bet the second number, you win the first number. So, in the first example, if you bet $1 you would win $10.

If at 5/2 fractional odds, you bet $4, you would also win $10 (for every value of the second number you bet, you win the first number plus the return of your stake).

Decimal Odds

Decimal odds are pretty straightforward. They’re like money—imagine you’re out shopping and you see something for $4.50, that’s equivalent to decimal odds of 4.50.

It’s an easier way to understand potential payouts based on a $1 bet. If something is 2.00 in decimal odds, you’d get double your money if you win.

It’s just another way of showing odds using decimals rather than fractions.

American Odds (also known as Moneyline)

In true American fashion, American odds are marching to their own beat! As you may have guessed, these odds work a bit differently than decimal odds and fractional odds.

In American odds, you’ll often see a plus or minus sign in front of a number, like +150 or -200.

If there’s a minus sign, like -200, that shows the amount you need to bet to win $100. On the other hand, if it’s a plus, such as +150, that means if you bet $100, you’ll win that amount.

It’s not like decimal odds; it’s more about how much you need to bet to win $100 or how much you’ll win on a $100 bet.

Commonly Seen Sporting Odds

Understanding odds and the science behind them has never been more important than in the world of sports betting. With the constant buzz around odds and lines, understanding

Points Spread

Think of the point spread like a head start in a race. Let’s say Team A is a strong runner, and Team B might need a bit of a boost to keep up.

The oddsmakers give Team A a head start of 3.5 points. If you bet on Team A and they win by more than 3.5 points, your bet wins.

If you bet on Team B, they need to win or lose by less than 3.5 points for your bet to win. It’s a way to even things out so both teams have a chance to attract bettors!


Also known as Over/Under, Totals are bets based on the combined score of both teams in a game. It’s not about who wins or loses but more about the total number of points scored by both teams together.

For instance, if a basketball game has a total of 180.5, you’re betting on whether the final score will be over or under that number.

It’s not just about picking the winner, but predicting whether the teams together will score more or less than the given total.


Futures bets are like crystal ball bets, looking way ahead into the future of sports events.

They’re not about a single game but more about predicting what could happen in the long run.

It’s like guessing who might win a big tournament even before the season starts or choosing the most valuable player of the season.

So, it’s a long-term bet about the future outcomes of events rather than just a single game.

Prop Bets

A favourite among Kiwis, prop bets like betting on the smaller details or side activities of a game. It’s not just about who wins or loses, but more like guessing specific things that might happen during the game.

For example, you can bet on whether a certain player will score a goal or how long the national anthem will be at the start of the game.

It’s a fun way to bet on various little moments and details during the game, not just the final score!


What Does It Mean When Odds Are Negative/Positive?

American odds can be your guide through the underdog story of sports betting. When odds have a plus sign (+) before the number, it indicates positive odds. It’s like cheering for the ultimate underdog. This might seem counterintuitive at first.

Think of it as rooting for the team with the odds stacked against them, marked as +200, for instance. If the positive odds team wins, you score more cash than your bet.

On the flip side, when you see the odds with a minus sign (-), it indicates negative odds. It’s like the team everyone expects to win. Betting on negative odds means you need to shell out more cash than you could win.

So, (+) odds equals potential big wins on the underdog, while (-) odds mean paying more to win on the favourite. Betting, like any game, is about understanding the odds and choosing your champion!

How Do Odds Correlate with Payouts?

Simply put, higher odds mean bigger payouts. Lower odds offer smaller rewards. The number you see in odds shows how much profit you’d make from a bet, depending on the amount you wager.

Big odds bring big wins, but they’re riskier. Small odds mean less risk but lower rewards.

It’s all about balance—picking the right odds for the kind of win you’re aiming for!

What Is a Betting Odds Calculator?

Like we said at the beginning, you don’t have to be a math wizard, there are tools for that!

A betting odds calculator helps predict potential wins based on the odds offered. It’s like a financial calculator but for betting. You enter the odds and the amount you plan to bet, and it tells you how much you could win.

The Bottom Line

Understanding odds gives you the superhero skills to predict outcomes and make smarter bets. You have just mastered the science behind betting odds. Now, whether it’s fractional, decimal, or American odds, you’re in the know.

Now you have the key to unlock the probability puzzle, and become a betting wizard who’s got the upper hand at the game table!

Understanding the significance of odds in fair gaming, strategic decisions, and house edge empowers you. Embrace this knowledge, play smart, and turn the odds in your favour. Happy betting!

Betting Odds FAQ

How do Sports Betting Odds Work?

Sports betting odds display the implied win probability and the potential payouts. They vary by format—decimal, fractional, or American odds.

Where Can I Find The Best Odds?

Find the best odds, visit our sports betting page, or check out our reviewed casinos for the most favourable odds.

For Casino games, you can check our list of the best online casinos in New Zealand to find out about game-specific odds.

How Are Betting Odds Determined?

Casino game odds are determined by the house to reflect the probability of various outcomes. They guide players on potential returns and are shaped by factors such as game rules and house edge.

For specific casino games, you can check our list of the best online casinos in New Zealand

What Are Good Betting Odds?

Generally speaking, if you are given odds better than one-in-two, it's a good bet. Good betting odds indicate a handsome payout relative to the risk. Higher odds suggest a lower probability, but potential for greater returns.

What Does 3 to 1 Odds Mean?

Odds of 3 to 1 mean if you bet $1, you win $3 plus your stake ($4 in total) if the bet is successful.

What Do Betting Odds of -200 mean?

Odds of -200 suggest a favourite, where you need to wager $200 to win $100, indicating a higher probability of success.

Why Do Betting Lines Move?

Betting lines move due to changes in factors such as player injuries, team performance, weather conditions, and betting volume.


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Lincoln Trembley
Lincoln Trembley
Betting Expert
28 Articles
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Lincoln is an expert in sports betting. With his skill and passion for trying our new brands in the iGaming industry, he frequently reviews sports betting sites and writes news about sports betting. Being a former sports trader, there’s not much he doesn’t know when it comes to sports betting.

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