Vig
The commission or margin built into betting odds by sportsbooks. Also called juice, overround, or margin. It's how sportsbooks guarantee profit regardless.
How Vig Works
On a fair coin flip, true odds would be +100 / +100 (even money both sides). But sportsbooks offer -110 / -110, meaning you risk $110 to win $100. That extra $10 is the vig.
Calculating Vig
Vig = (1 - (1 / (Implied Prob A + Implied Prob B))) × 100
For -110 / -110:
- Implied prob each side: 110/210 = 52.38%
- Total: 104.76%
- Vig: 4.76%
Why It Matters
The vig is the house edge. To be profitable long-term, you need to overcome the vig by finding +EV bets or arbitrage opportunities where the combined vig across books creates exploitable gaps.
Low-Vig Sportsbooks
Sharp books like Pinnacle, Circa, and betting exchanges offer lower vig (1-3%) compared to recreational books (5-10%+). Lower vig means better odds for bettors.