How Betting Odds Work

Decimal odds show you exactly how much you win back with your stake, your profit, and the implied probability in the price. This means if you place a R100 bet at 2.50, you will get back R250. The R150 is your profit, the R100 is your stake returned.

What do Decimal Odds Mean?

Decimal odds are the most straightforward and popular format in South African sports betting. They give you the total return on the odds for every R1 you stake.

• R100 bet at 2.50 returns R250 in full, made up of R150 profit and your R100 stake.
• R100 stake at 1.25 returns R125, so the profit is R25.

Sometimes decimal odds are shortened to just the digits after the decimal point, or given without the decimal. This is most common in horse racing or other fast-finishing bets by phone, text or handheld device. So to add or insert the decimal point:

• If you see odds listed as ‘3/1’ or just ‘3’, that means 3.00 or 4.00, a stake of R1 multiplied by 3 for a total return of R4 including the stake.
• As the scorebet.co.za explainer says, “In general, common decimal odds you will see are 1.25 (fractional: 1/4), 1.33 (fractional: 1/3 or 2/6), 1.50 (fractional: 1/2), 1.2 (fractional: 2/5), 2.00 (fractional: 1/1, or even money), 2.50 (fractional: 1/2 or 2/4), 3.00 (fractional: 2/1), 4.00 (fractional: 3/1), and 5.00 (fractional: 4/1).”

Implied Probability in Decimal Odds

Decimal odds are a bookmaker’s unique price, reflecting their unique judgment of two things: the chance the team or horse will win, and the spread they want between their estimated price and the payout you receive. That is why implied probability does not give the same odds a bookmaker does. Mathematically, you calculate implied probability as 1 divided by the decimal odds.

To illustrate: a bookmaker sets odds of 4.00. That calculates to 25 percent for the implied probability. But the bookmaker did not start from a 25 percent price point. A 25 percent probability tip should trade at 3.00, where 1 divided by 3 equals 33 percent. Price inflation is intentional. Bookmakers create a cushion by setting the odds at a higher number than implied probability, and for more than just this one selection, for multiple outcomes that add up. The overround is how they make a profit on their margins.

What is Bookmaker Margin?

The total of all the implied probabilities in a market adds up to more than 100 percent. In a market with three outcomes, for example, a bookmaker may price the aggregate as 340 percent on the event price. It makes no difference to the profit to a punter who bets on one outcome - their odds are whatever is priced, as invested. But to the bookmaker, the excess represents their profit margin, or overround, from the differential of how they price, and the excess of 100 percent that winds up being available after the winners are invested back. That is called the bookmaker’s margin or overround in the figure scorebet.co.za calls it on this explainer page.

How Accumulators Ladder in Decimal Odds

A multiple bet, also known as an accumulator, acca, call, or parlay, is a bet on two or more independent outcomes. It can be a great way to multiply a parlay of favorites, but with the risk that even one leg will ruin the win. Each leg in a multiple must win, or it voids the outcome.

If one leg is priced at odds of 2.00, the next leg of the accumulator at 2.00, and a third at 2.00, your odds on the accumulator of three legs multiply to 8.00. But punters think of accumulators as multiplying the profit from the odds, not multiplying the total return.

1. R100 bet on an accumulator with three legs at 2.00 each will multiply to 8.00 in total odds on the stake.
2. 8 times R100 is R800 total return.
3. That’s R700 of profit on top of your original stake.

Minus the risk of one weak link, and people chase the math on that rather than the price.

Help is available for gambling problems from the free South African National Responsible Gambling Programme at 0800 006 008, open 24 hours a day 7 days a week.