Odds PiranhaNo-Vig Odds & Devigging
Core concept · Updated August 2026 · ~6 min read
Sportsbooks don't publish what they actually think will happen. They publish that estimate plus a markup — the vig. If you can subtract the markup, you're left with the book's honest opinion of each side's probability. That "no-vig" or "fair" line is the closest thing to a free, accurate probability estimate in all of betting, and it's the reference point +EV betting is built on.
What the vig actually is
Price a coin flip at −110 on both sides. Each side implies 52.4%, so the two add up to 104.8%. That surplus 4.8% is the overround (or hold, or juice) — the book's commission baked into the prices. On a fair coin the true odds are +100 / +100 (50% each), but you're paying −110 for a 50% shot, which is why the average bettor slowly bleeds even when they pick winners half the time.
Removing the vig (the two-sided method)
The simplest devig takes both sides' implied probabilities and rescales them so they sum to exactly 100%.
Team A is −150 (implied 60.0%). Team B is +130 (implied 43.5%). Total = 103.5% — that's 3.5% of vig.
No-vig A = 60.0 ÷ 103.5 = 58.0%. No-vig B = 43.5 ÷ 103.5 = 42.0%. Those two now sum to 100%, and 58% converts back to a fair price of about −138.
So the book's true read on Team A is ~58%, not the 60% the raw price implied. If another book is offering Team A at −130 (implied 56.5%), you're getting a price better than fair — a +EV bet.
Whose line should you devig?
Not all books are equal. A recreational ("soft") book shades its lines to bait the public and bakes in a fat hold. A sharp book — Pinnacle, Circa, and the betting exchanges at their most liquid — takes big bets, moves fast, and prices tight. The no-vig line at a sharp book is the gold-standard probability estimate. Devigging a soft book tells you very little; devigging the sharp book and comparing it to soft books is where edges appear.
The simple two-sided devig slightly overstates favorites and understates longshots; more advanced methods (like the "power" method) correct this favorite–longshot bias. And devigging is only meaningful on a tight, two-sided, current market — a wide or stale quote gives a garbage fair line.