What Is a Parlay Bet?
A parlay combines selections into one ticket. All active legs must win for a winning payout; a losing leg makes the ticket lose. Higher offered returns do not establish positive expected value. Separate the payout calculation from the probability that all legs succeed.
How Parlay Payouts Are Calculated
For the product-of-prices calculation used in these OwnTheLines examples, convert each American quote to decimal odds. At +200, D = 1 + 200/100 = 3. At -110, D = 1 + 100/110 = 21/11 ≈ 1.9091.
Multiply the exact decimal prices and the stake to calculate total return if every leg wins. Subtract the stake for net profit. This is a payout rule, not a claim that the outcomes are independent; an external operator’s quoted correlated-parlay price may differ.
| Hypothetical $100 ticket | Exact return calculation | Total return | Net profit if all win |
|---|---|---|---|
| Two -110 legs | $100 × (21/11)^2 | $364.46 | $264.46 |
| Three -110 legs | $100 × (21/11)^3 | $695.79 | $595.79 |
The exact three-leg multiplier is about 6.957926. Equivalent American odds are approximately +596. Keep full precision before rounding; displayed cent amounts are illustrative and settlement follows the application’s rounding rules.
Joint Probability and Correlation
For independent events with assumed win probabilities p1, p2, and p3, P(all win) = p1 × p2 × p3. Without independence, use conditional probabilities: P(A and B) = P(A) × P(B given A). Each probability must describe the correct selection and settlement outcome.
Hypothetical example: if two events each have probability 50% and are independent, both win 25% of the time under that model. If P(B given A) is instead 70%, their joint probability is 0.50 × 0.70 = 35%. Multiplying the two marginal probabilities would be wrong.
See MIT’s conditional-probability and independence notes for the multiplication rule. Correlation is not automatically an exploitable advantage; the offered payout may already account for it.
Higher Payout Is Not Positive EV
Assume three independent legs each truly have a 50% win probability, each is priced -110, and there are no pushes, voids, fees, or taxes. Joint win probability = 0.5^3 = 12.5%. Expected net profit on $100 = 0.125 × $695.792637 - $100 ≈ -$13.03.
That calculation uses total return in p × return - stake. Equivalently, weight the $595.792637 net win by 12.5% and the $100 loss by 87.5%. It describes only these assumptions, not an observed loss rate or a universal parlay edge.
Read statistical variance to distinguish a single result from a probability model.
What Happens When a Leg Pushes?
On OwnTheLines, a push leg is removed and the remaining legs determine the outcome using their combined odds. If all legs push, the stake is returned. If any remaining leg loses, the ticket loses. A push is not a winning leg at its original multiplier.
Same-Game Leg Rules
For legs from one game, at most one moneyline, one spread, and one total are allowed. Spread+total and moneyline+total are permitted. A moneyline and spread on the same team are rejected; on opposing teams they are allowed only when the spread selection is the underdog (positive line).
Eligibility under the application’s rules is separate from probability independence. Do not treat an allowed same-game combination as evidence that multiplying marginal win probabilities is justified.
Parlay or Box?
A Box Wager splits its total stake among combinations. Some combinations can pay while the overall box still loses money. Neither a larger headline return nor a partial payout establishes positive EV.
For the underlying price notation, see American Odds Explained.
Frequently Asked Questions
How are parlay payouts calculated?
For a product-priced parlay, multiply the legs' exact decimal prices and then the stake. Two -110 legs return about $364.46 on $100; three return about $695.79. Those are total returns including stake, rounded only for display; settlement follows the application's rounding rules.
Can I multiply the legs' win probabilities?
Only if the events are independent under the model. Otherwise use conditional probabilities or a justified joint model. The displayed payout multiplier does not establish the probability that every leg wins.
Does a higher parlay payout mean positive expected value?
No. Expected net profit depends on both the offered return and the assumed joint win probability. Correlation and errors in the probability estimates can change the conclusion.
What happens when a leg pushes on OwnTheLines?
A push leg is removed from the parlay. The remaining legs determine its outcome at their combined odds. All legs pushing returns the stake; any remaining losing leg makes the ticket a loss.