Glossary
Fair Line
The fair line is the true price of a bet with the sportsbook's profit margin stripped out. We build it by "de-vigging" Pinnacle — widely considered the sharpest book in the world — to reveal what the market actually thinks the real probability is, not what a book needs to charge to guarantee itself a profit.
In practice
Say two evenly-matched teams are both priced at -110 by a book. That implies 52.4% each — 104.8% total, with the extra 4.8% being the house's cut. De-vig that down proportionally and you get a fair line of roughly 50/50 each.
Why it matters here
Every other number on this site is measured against this one. A book "beating fair" means it's paying you more than the true odds justify — that gap, not a prediction of who wins, is the entire product.