The Basics of Odds at Online Casinos and Sportsbooks

Wed, Mar 13, 2024
by CapperTek

The two most important things any online casino player or sports bettor needs to get to grips with before playing games or placing sports bets are the betting odds and the implied probability rate of an outcome/result actually occurring.

Understanding this basic information can lead to more strategic betting decisions, which can also help you hold on to your bankroll for longer periods and place fewer silly bets/wagers on outcomes that are less likely to occur.

Let's dive straight in to discover more about the basics of odds and IPRs (implied probability rates) you will most likely come across on today's most trusted iGaming sites.

How do betting odds work at online casinos and sports betting sites?

The thing to remember about online sports betting sites and casinos is that the betting odds you are offered for any sporting event are the ratio between the total amount of money wagered by the bookmaker and the bettor.

Therefore, 5/1 in the fractional odds format, which is +500 in the American/moneyline odds format and 6.00 in the decimal odds format, means the bookmakers (betting operators) wager five times the amount the bettor has wagered.

If the bettor's wager wins, the outcome that they initially predicted before the event started occurs means they will receive winnings worth five times their initial wager AND their initial stake returned on top of the winnings.

When it comes to the RTP (Return to Player) percentage payout rate in online casino games, it works in a slightly different way.

The RTP% value tells us roughly how much an online casino game is likely to pay out in the percentage form after a certain amount of money is wagered on that game. Also, the RTP percentage is calculated in the opposite way as the house edge is calculated.

It sounds a lot more difficult than it actually is, and when I first had to get my head around all these different numbers and percentages, it was overwhelming, but it didn't take too long at all.

An example of RTP/house edge may appear like this: the house has a 4.00% edge over the player (as listed in the game's payout structure).

In this case, the same game's RTP% value would be the remainder of that amount, minus 100; therefore, in this case, the RTP% payout rate for that game would be 96.00%. The 96.00% RTP is the average amount a player's wager is expected to be returned. Try not to let this confuse you.

For example, the highest RTP online slots (so the games that are MORE LIKELY to pay compared to low RTP slots) normally have a 98.00% RTP% payout rate or higher. Average is considered between the 93.00% to 98.00% range, and low is considered anything lower than 93.00%.

How can I make understanding the odds at online sports betting sites easier?

The best thing about most online sports betting sites today is that you can actually change how the odds are displayed on the website. Just look for the betting odds format button and toggle between fractional, decimal, or American/moneyline odds.

I was brought up with the fractional odds format, which is popular in the UK. However, when I tried out the decimal odds format, I found it much easier to understand.

In other words, although the fractional odds format is more popular in the United Kingdom, it doesn't mean you have to use this system.

If you hadn't already guessed, the American/moneyline odds format is more prevalent in North America (the United States and parts of Canada), and the decimal odds format is popular elsewhere (e.g., India, South Africa, Australia, Europe, etc.).

Remember that the higher the implied probability rate, the more likely that outcome/result will occur (but it's still not guaranteed). Let's take a quick look at a few examples.

A betting market with 5/1 fractional odds translates to 6.00 in decimal odds and +500 in American/moneyline odds. The Implied probability rate for these odds is 16.70%. Here are some more examples:

        Fractional odds: 1/4. Decimal odds: 1.25. American/moneyline odds: -400. Implied probability rate: 80.00% (very likely to occur)

        Fractional odds: 10/11. Decimal odds: 1,91. American/moneyline odds: 110. Implied probability rate: 52.40% (almost 50/50 chance of occurring)

        Fractional odds: 66/1. Decimal odds: 67.00. American/moneyline odds: +6,600. Implied probability rate: 1.50% (very unlikely to occur)

It's pretty much the same in casino games but appears slightly different. For example, you may see the phrase 'Blackjack pays 3:2,' which is essentially saying it pays one and a half times your stake.

In roulette, a straight-up bet might pay 35:1, which means you would get 35x times your initial stake. It's the same as saying 35/1 (fractional odds), 36.00 (decimal odds), or +3,500 (American/moneyline odds), with only a 2.80% chance of occurring (implied probability rate).

In comparison, a winning red/black/ or odd/even bet in roulette normally pays 1:1, which is the same as saying 1/1 (aka evens, in fractional odds), 2.00 in decimal odds, and +100 in American/moneyline odds, with a 50% IPR.

As you can see, understanding the basic odds at online casinos and sports betting sites is relatively straightforward, although it may seem rather confusing for beginners.

Once you have mastered one particular format, placing sports bets should be a lot easier, and the bets you place will be more informed bets with a greater chance of returning a profit.