How Betting Odds Work (South African Guide)
Reviewed for responsible-gambling compliance by Priya Naidoo.
Odds are just a number, but they tell you two things at once: how much a bet pays and how likely the bookmaker thinks an outcome is. Once you can read them, you can spot when a price is fair and when it is not.
South African bookmakers such as Hollywoodbets, Betway and Supabets show decimal odds by default, so that is what we focus on here, with every example worked in rand.
What do decimal odds actually mean?
Decimal odds show the total return for every R1 you stake, and crucially that figure includes your stake back, not just the profit. Odds of 2.00 mean a R100 bet returns R200 in total: your R100 stake plus R100 profit. Odds of 1.50 return R150, so R50 profit, and odds of 4.00 return R400, which is R300 profit on top of your stake. The higher the number, the less likely the bookmaker thinks the outcome is, and the bigger the payout if it lands. A short price such as 1.20 marks a strong favourite expected to win most of the time, while a long price like 9.00 marks an outsider the bookmaker expects to lose. For example, 1.20 implies over 80 percent, so the R20 profit on R100 reflects how little risk the bookmaker attaches to that result.
How do you turn odds into implied probability?
Every set of odds hides a probability, and finding it is the single most useful habit in betting. To do it, divide 1 by the decimal odds and read the answer as a percentage. Odds of 2.00 give 1 divided by 2.00, which is 0.50, or a 50 percent chance. Odds of 4.00 give 0.25, a 25 percent chance, and odds of 1.25 give 0.80, an 80 percent chance. Once you can do this quickly, you can compare the bookmaker's view with your own. If you think a team has a better chance than the odds imply, the price may offer value worth taking. If the odds imply a higher chance than you honestly believe is real, it is a poor bet however tempting the payout looks. The caveat is that these implied figures add up to more than 100 percent across a market, thanks to the margin.
Odds, probability and payout at a glance
| Decimal odds | Implied chance | Return on R100 | Profit on R100 |
|---|---|---|---|
| 1.20 | 83% | R120 | R20 |
| 1.50 | 67% | R150 | R50 |
| 2.00 | 50% | R200 | R100 |
| 3.20 | 31% | R320 | R220 |
| 4.00 | 25% | R400 | R300 |
| 9.00 | 11% | R900 | R800 |
How are payouts calculated?
- Single bet: R50 at odds of 3.20 returns R50 x 3.20 = R160 in total, which is R110 profit once you take your stake back out.
- Favourite: R200 at odds of 1.40 returns R200 x 1.40 = R280 in total, a slim R80 profit that reflects the short price.
- Outsider: R30 at odds of 7.50 returns R30 x 7.50 = R225 in total, a large R195 profit that reflects the long odds.
- The formula never changes: stake multiplied by decimal odds gives your total return, and total return minus stake gives your profit.
Why are the odds never perfectly fair?
If you add up the implied probabilities of every outcome in a market, they come to more than 100 percent, and that extra slice is how the bookmaker makes money. It is called the margin, or the overround, and it is baked into every price you see. On a two-way market such as a tennis match, a truly fair coin-flip would be 2.00 and 2.00, but you are far more likely to be offered 1.90 and 1.90. Those prices imply about 52.6 percent each, adding to roughly 105 percent, and that extra 5 percent is the operator's built-in edge. For example, staking on both sides at 1.90 guarantees a small loss, which is the margin at work. This is exactly why staking discipline and hunting for value matter more than any single bet: the house edge only shows up over the long run.
Frequently asked questions
Do decimal odds include my stake?+
Yes. Decimal odds show your total return, which already includes the stake you put down. At odds of 2.00 a R100 bet returns R200 - that is your R100 stake back plus R100 profit. To find profit alone, subtract your stake from the total return, so R200 minus R100 leaves R100 in winnings.
What do odds of 1.50 mean in rand?+
Odds of 1.50 return R1.50 for every R1 you stake, including that stake back. So a R100 bet returns R150 in total, which is R50 profit on top of your R100. A R200 bet at the same price returns R300, for R100 profit. Short odds like these mark a strong favourite, so the profit margin is small relative to the risk.
How do I work out probability from odds?+
Divide 1 by the decimal odds and read the result as a percentage. Odds of 4.00 give 1 divided by 4.00, which is 0.25, so the implied chance is 25 percent. Odds of 2.00 give 50 percent, and odds of 1.25 give 80 percent. Comparing this implied chance with your own honest estimate is how you spot whether a price offers value.
What is the bookmaker margin?+
The margin, or overround, is the extra slice built into every market so the bookmaker profits over time. Add up the implied probabilities of all outcomes and they exceed 100 percent - a two-way market priced at 1.90 and 1.90 totals about 105 percent. That extra 5 percent is the house edge, which is why shopping for the best odds pays off.