What Is a Parlay in Betting?

Parlay Math, Step by Step

Convert each leg to decimal odds and multiply. Three spread bets at -110 are 1.909 each: 1.909 x 1.909 x 1.909 = 6.96. A C$20 parlay returns C$139.15, a profit of C$119.15, about +596 in American odds. Mixed tickets work the same way: -145 (1.69), +160 (2.60) and -110 (1.91) combine to 8.39, so C$10 returns C$83.90.

Now the probability side. If each -110 leg is roughly a coin flip, the parlay hits 0.5 x 0.5 x 0.5, or 12.5% of the time. Fair odds on a 12.5% event are 8.00, but the book pays 6.96. The gap means the effective house edge is about 13%, nearly triple the single-bet cost. Every added leg compounds it further: a five-leg -110 parlay carries an edge over 20%.

Parlays have deep Canadian roots. Until the Criminal Code changed in August 2021, provincial lottery products like Proline could only offer parlays, so an entire generation of Canadian bettors grew up multiplying legs by necessity. The legalization of single-game betting is precisely what made straight bets available, and the math says most tickets should now be straight.

Same-Game Parlays and Sensible Use

Same-game parlays bundle correlated outcomes from one event, like McDavid over 1.5 points, Oilers moneyline and over 6.5 goals. Books reprice correlated legs rather than simply multiplying, and the repricing is where margins quietly reach 15% to 20%. SGPs are the industry's fastest-growing product because they feel like insight and price like a lottery ticket.

Used knowingly, parlays are fine entertainment: small stakes, big potential payouts, sweat all night. The discipline rules are simple. Keep stakes to a fraction of your normal unit, cap tickets at two to four legs, and never parlay to chase losses, because the compounded margin makes it the most expensive possible way to recover. If a bet matters to your bottom line, bet it straight.