Decimal odds and gross return
Multiply a stake by decimal odds to calculate gross return if a single selection wins. At 2.50, a R10 winning single returns R25 gross, including the R10 stake. This is not guaranteed; a selection can lose and an accepted price can change.
The reciprocal of decimal odds is a simple implied probability before margin. At 2.50 it equals 40%. That translation is not an objective statement that the outcome has exactly a 40% chance.
Overround and limits
For mutually exclusive outcomes in a complete market, add their implied probabilities. If the sum exceeds 100%, the excess is often called overround. It can compare displayed prices at one time, but does not reveal future operator profit.
Do not combine a two-way market with a three-way one, or prices with different periods, lines or promotion conditions.
A fair comparison record
Record event, market wording, line, timestamp, operator, price, accepted price and stake restrictions. Compare only the same proposition under similar rules and repeat across a meaningful sample before claiming a lasting difference.
This guide did not benchmark Betway. A favorable price cannot guarantee a win, and no arithmetic removes the risk of losing the stake.