What is a no-vig price, and how do you work it out?
A no-vig price is a line's price with the sportsbook's margin taken out. Turn both sides into implied chances, add them up, and divide each side by that total. The results add up to 100% and are the market's fair estimate.
Example 1: -110 / -110
Each side implies 52.38%. Together: 104.76%. The extra 4.76% is the vig.
Divide each by 1.0476: 50% and 50%. The fair price is +100 on both sides.
Example 2: -150 / +130
Over -150 implies 60.0%. Under +130 implies 43.48%. Together: 103.48%.
Fair chances: Over 60.0 ÷ 103.48 = 58.0%, Under 42.0%. As prices: about -138 and +138.
Why it matters
Comparing your own estimate with the fair chance, not the raw price, tells you whether a bet is priced well. A parlay's true price is the product of the legs' fair chances, which is how PropLab's Slip check reads a slip.
This simple method splits the margin evenly. Other methods put more of it on the longer side; the difference is small near even money.
Questions
Can I get a no-vig price for a one-sided bet?
Not directly: you need both sides. For an alt-line ladder or an anytime touchdown, you can only estimate the margin from similar two-sided lines.
Is the no-vig price always right?
No. It is the market's best guess at that moment. Closing no-vig prices are usually the sharpest.