What Is Vig Sports Betting?
“Vig” (short for vigorish)—also called “juice” or “margin”—is the built‑in fee sportsbooks charge for taking your action. It’s the invisible rake that turns an otherwise 50/50 market into a long‑term edge for the house. Understanding how vig is priced, calculated, and reduced is essential for any bettor who hopes to profit consistently.
What Is Vig?
- Definition: The difference between true 50‑percent odds and the price a sportsbook offers, ensuring it earns revenue regardless of the game outcome.
- Location: Hidden inside the odds—spread lines, moneylines, totals, props, parlays, everything.
- House Edge: Average U.S. hold after vig is about 5–7 % of handle, but varies by sport and market.
How Sportsbooks Set Vig
Most spreads and totals open at –110 / –110. When equal money comes in on both sides, the book keeps the vig:
- $110 risk to win $100 (implied win probability 52.38 %)
- Combined implied probability for both sides = 104.76 %
- Excess 4.76 % = vig
If action skews, the book may shade the line or adjust price (e.g., –115/–105) to balance liability while maintaining similar margin.
Vig on Point Spreads: Step‑by‑Step Calculation
| Side | Odds | Decimal | Implied Probability |
|---|---|---|---|
| Team A –3.5 | –110 | 1.909 | 52.38 % |
| Team B +3.5 | –110 | 1.909 | 52.38 % |
Total implied probability = 104.76 %. Remove 100 % and you get a 4.76 % house margin. Convert back to “fair odds” by dividing each implied probability by 104.76 %, then converting to American or decimal format—this yields vig‑free prices you can compare across books.
Vig on Moneylines: Favorite vs. Underdog Example
- Favorite: –150 → decimal 1.67 → implied 60.0 %
- Underdog: +130 → decimal 2.30 → implied 43.5 %
Total implied probability = 103.5 %; margin = 3.5 %. Favorite/underdog splits often carry lower raw margin than –110 spreads but higher effective hold due to uneven bet distribution.
Vig, Hold, and Margin—What’s the Difference?
- Vig/Margin: Theoretical edge per market, assuming balanced action.
- Hold: Realized percentage of handle kept after results settle.
- Overround: European term for combined implied probability >100 %—same as margin.
Strategies to Reduce Vig
- Line‑Shopping: Compare multiple sportsbooks; even –105 vs. –110 turns a coin‑flip from –2.38 % EV to –1.90 %.
- Reduced‑Juice Books: Some operators offer –107, –105, or even +100 promos on spreads.
- Alt Lines: Pay fewer cents by buying or selling half‑points strategically around non‑key numbers.
- Exchange Betting & P2P: Liquidity‑driven markets (e.g., Betfair) let you lay bets at near‑zero juice.
- Promos & Boosts: Odds boosts can flip negative EV into positive, effectively canceling vig on that selection.
Effect of Vig on Long‑Term ROI
Consider a bettor hitting spreads at 54 % win rate:
- At –110 odds, break‑even win rate is 52.38 %; edge = +1.62 %
- At –105 odds, break‑even = 51.22 %; edge = +2.78 %
Takeaway: Reducing vig by five cents nearly doubles profit margin for the same predictive accuracy.
Vig in Parlays, Teasers & Same‑Game Parlays
- Parlays: Fixed‑payout tables compound vig on each leg; true margin often 20 %+
- Teasers: Extra points cost extra vig; break‑even for 6‑pt, 2‑team teaser around 73.9 %
- SGPs: Correlated legs carry even steeper hidden juice, offsetting perceived “boosted” payouts.
Frequently Asked Questions
Can vig ever be zero?
Yes—rare “no‑juice” promos or exchanges where supply and demand set prices. Books may also post 0 % vig lines during early openers to attract action, then adjust later.
Why does vig vary by sport?
Liquidity, volatility, and bettor demand differ. Niche sports carry higher margins (8–12 %) while NFL sides/totals can dip below 4 % at sharp books.
Are live‑betting vigs higher?
Generally yes. In‑play odds change rapidly and data fees are higher, so books bake in a few extra cents to cover risk.
Does vig apply to props and futures?
Absolutely. Props can exceed 20 % margin; futures often surpass 30 % when the field is summed.
Key Takeaways
- Vig is the sportsbook’s built‑in fee, hidden inside every price.
- Standard –110 lines equal a 4.76 % margin; knowing this lets you calculate fair odds.
- Shopping for reduced juice or better lines directly boosts long‑term ROI.
- Vig compounds in parlays, teasers, props, and futures—stay vigilant.
- Focus on cutting vig first; even small price improvements can double your profit edge without changing your model.
