Parlay odds chart: payout and book hold by leg count

How to read the parlay odds chart

Three columns matter and the rest are working. The first is what the book pays. The second is what the same legs would pay if the prices carried no margin. The last is the gap between them as a share, which is what the book keeps.

Take three legs. The offered price is +595 and the fair price is +700. On a $100 ticket that is $695.79 against $800, so the book keeps $104.21, or 13.03%. On a single bet at the same price it keeps 4.55%. Nothing changed except the number of legs on the slip.

By six legs it keeps 24.36%. By ten it keeps 37.20%. By twelve it keeps 42.78%, so the ticket returns a little over half of what a fair price would return, and the chart runs that far specifically because long parlays are marketed hardest.

Why it compounds

Each leg is priced with the same margin, and multiplying prices multiplies margins. The retained share is one plus the market margin raised to the power of minus the leg count: at 4.7619% and three legs that is 86.97%, so 13.03% is kept.

Because it compounds instead of adding, intuition is a poor guide. Most people expect doubling the legs to roughly double the cut. It does considerably more than that at the short end and considerably less at the long end, which is exactly the shape a table conveys better than a sentence.

The practical consequence is that the price of each leg matters more on a parlay than anywhere else. Legs taken from tightly priced main markets compound a smaller number. Legs taken from props, where holds of 8% to 20% are ordinary, compound a much larger one, and a four-leg prop parlay can cost several times what this chart shows.

What the chart assumes

Two assumptions, both worth stating because both fail in common situations.

Every leg is priced at −110 on both sides of its market. That is the American standard for spreads and totals and it is a reasonable default, but it is a default. Real tickets mix prices, and the parlay calculator takes the actual ones.

The legs are independent, so their probabilities multiply. This is true for legs drawn from different games and false for legs drawn from the same one. Same-game parlays are priced through a correlation model, and the arithmetic here will overstate what they return, often substantially.

One thing the chart does not say is that parlays are a mistake. It says what they cost. A ticket bought for entertainment at a known price is a different proposition from one bought under the impression that the payout figure is the whole story, and the difference between those two is the only thing this page is for.

Two habits make the chart useful instead of merely alarming. The first is to read across before reading down. The interesting comparison is not between two leg counts but between the offered price and the fair price on the same row, because that pair is the actual cost of the ticket in the units the ticket is sold in.

The second is to convert the percentage into money on the stake you would really use. A 24.36% hold is abstract; on a $100 six-leg ticket it is $1,558 of foregone fair payout, and those two sentences state the same fact with very different force. The dollar columns exist for exactly that reason.

It is also worth knowing where the chart is conservative. Every row assumes legs priced at the tightest standard American market. Parlays built from props, alternate lines or same-game markets carry wider margins per leg, so they compound a larger number and the real figures sit above this table rather than below it. A four-leg prop parlay can cost more than the eight-leg row shown here.