Parlay Bets Explained: Combined Odds and the Hidden Margin

A parlay combines two or more selections into a single bet. Every selection has to win for the bet to pay out, and in return the odds are multiplied, which is why parlays promise large returns from small stakes. Since single-event wagering became legal in Canada in 2021, parlays are no longer the only option, but they remain popular.

How the odds are calculated

In decimal format the price of a parlay is simply the product of the individual prices. Three selections at 1.80, 2.10 and 1.50 give a combined price of 5.67. The potential return grows quickly, but so does the probability that at least one leg fails. A parlay with five evenly matched legs wins less than one time in thirty.

The bookmaker’s margin

Each selection carries the bookmaker’s built-in margin. When selections are multiplied, the margins multiply too, so the total margin on a parlay is higher than on any of its legs taken alone. This is the main reason experienced bettors treat parlays as entertainment rather than as a value play.

Voided legs and same-game parlays

If an event is cancelled or a selection is voided, that leg is removed and the parlay is settled on the remaining legs at a lower price. Same-game parlays, which combine outcomes from one match, are priced differently because the outcomes are related: a team winning and its striker scoring are not independent events, and operators adjust the odds accordingly.

Licensed Canadian operators must show the combined odds and the maximum payout before a parlay is placed, so the cost of each extra leg is visible in advance.