Decimal odds show a possible total return relative to a stake. They are a price offered by a bookmaker, not a prediction or promise.
Decimal odds and returns
At decimal odds of 2.50, a R100 winning stake would return R250 in total: the R100 stake plus R150 in winnings. If the selection loses, the R100 stake is lost. Always distinguish total return from profit.
Implied probability
A simple implied probability is calculated as 1 divided by the decimal odds. Odds of 2.00 imply 50%; odds of 4.00 imply 25%. This conversion helps compare prices, but the percentages across all outcomes usually add to more than 100% because the bookmaker builds in a margin.
The bookmaker margin
Suppose two outcomes are both priced at 1.91. Each implies about 52.36%, for a total above 104%. The amount above 100% is an indicator of the market margin before other factors. Different markets and operators can have different margins.
Odds move
Prices may change as information, trading decisions and customer activity change. Shorter odds do not prove that an outcome will occur. A market can move in the expected direction and still lose.
Practical checks
- Confirm whether the displayed figure is decimal odds.
- Check settlement rules, dead-heat rules and whether extra time counts.
- Compare the same market and conditions, not merely similar labels.
- Calculate the maximum loss before placing the bet.