The most common silent leak in sports betting is not a bad beat. It is pricing.
Sportsbooks are not just predicting outcomes. They are selling prices on outcomes, and the fee built into those prices is the vig. Over enough bets, that fee is often the difference between a strategy that looks solid and one that is mathematically guaranteed to drift downward unless you consistently have a real edge.
What is vig?
The vig (short for vigorish, also called juice) is the sportsbook's built-in margin. It shows up because the implied probabilities across a market add up to more than 100% — which raises the win rate you need to break even and lowers your expected payout on every bet.
Vig is the price you pay for access to a betting market. You never see it as a separate line item. Instead, the sportsbook builds it directly into the odds, so payouts are slightly worse than "true" fair odds would be.
A clean way to understand this: in a perfectly fair market, the total implied probability across all outcomes would equal exactly 100%. When it totals more than 100%, the excess is the bookmaker's margin.
How vig shows up in betting odds
To see vig, convert each side's odds to implied probability and add them up.
Two-way markets (spreads, totals, most props)
The classic example: both sides at −110.
−110 implies: 110 ÷ (110 + 100) = 52.38%
Two sides at −110: 52.38% + 52.38% = 104.76%
That 4.76% above 100% is the vig. The sportsbook has a mathematical edge on every bet before the game is even played.
This is why standard spread pricing means winning 50% of bets is not break-even — you need 52.38%.
Moneylines and multi-way markets
Vig works the same way but is less symmetrical. Example: −170 / +150.
- −170 implies: 170 ÷ 270 = 62.96%
- +150 implies: 100 ÷ 250 = 40.00%
- Total: 102.96% — the 2.96% is the hold
The margin varies by market and pricing. Futures boards often have implied probability totals well above 110% — sometimes 130–140% across all listed outcomes.
What the vig actually costs you
Break-even win rates by price
| Odds | Break-even win rate |
|---|---|
| −105 | 51.22% |
| −110 | 52.38% |
| −115 | 53.49% |
| −120 | 54.55% |
| −125 | 55.56% |
| −130 | 56.52% |
A move from −110 to −120 is not cosmetic. It changes your required accuracy by more than two percentage points — a meaningful hurdle in any market where edges are small.
In real dollars at 1,000 bets
Winning 52% at −110 (risk $110 to win $100):
EV per bet = (0.52 × $100) − (0.48 × $110) = −$0.80- 1,000 bets: approximately −$800 even winning more than half
Winning 53% at −110:
EV per bet = (0.53 × $100) − (0.47 × $110) = +$1.30- 1,000 bets: approximately +$1,300
A single percentage point of win rate is the difference. The vig is why that gap is decisive.
Where vig gets larger, and why casual bettors underestimate it
Standard spreads and totals at −110/−110 carry roughly 4.8% hold — the reference point.
Props typically carry more. Common prop pricing of −115/−115 raises hold to ~6.5%; −120/−120 pushes it above 9%. Some exotic or algorithm-generated props carry 10–20% hold.
Parlays compound vig across every leg. The sportsbook's expected hold on a 3-leg parlay at −110/leg is approximately 10–12% — two to three times the hold on a straight bet.
Futures are often the worst. A full-market futures board may have combined implied probabilities of 130–140%, meaning the book has structured the menu to guarantee itself a substantial return.
Longshots and low-probability outcomes can be priced with extra margin beyond what the overround implies. If a 15% true probability is priced as 12% implied, the bettor is paying extra just for the lottery-style format.
Common mistakes vig creates
Treating a good read as the same thing as a good price. They are not. You can correctly identify a team as the better side and still lose money long-term if you're consistently paying bad prices.
Over-betting props and parlays because they're entertaining, without tracking the hold embedded in each market.
Ignoring small pricing differences across sportsbooks as if they're trivial. At volume, a 5-cent difference per bet — say, −108 vs. −113 — adds up to hundreds of dollars across a season.
Practical steps to reduce vig cost
Convert odds to implied probability before every bet. If you can't convert −110 to 52.38% quickly, you're guessing about the real hurdle the price creates.
Treat price as part of the bet, not an afterthought. Higher margin directly means poorer value, regardless of how well you handicap the outcome.
Line shop. Consistently. A move from −110 to −105 on the same wager drops your break-even from 52.38% to 51.22%. That is a structural improvement that doesn't require any change in your analysis.
→ Line Shopping: How to Get Better Prices
Audit where you pay the worst prices. If your bet log shows heavy volume in high-hold markets — exotic props, live betting, same-game parlays — the vig may be doing most of the damage, not your reads.
Use no-vig probabilities when comparing your estimate to the market. Raw implied probability includes the margin. When you compare your estimate to it, you're comparing your number to a padded one.
→ Implied Probability: How to Calculate It and Remove the Vig
Frequently Asked Questions
Is vig the same as juice? Yes. In US betting, vig and juice both refer to the bookmaker margin built into the odds. Overround and hold are closely related terms that describe the same concept.
Why do most spread bets sit at −110? Because pricing both sides at −110 creates an overround above 100%, which is the embedded hold for the sportsbook. It has become the default standard for most US markets.
Is −110 a 10% fee? Not exactly. The "risk $110 to win $100" convention describes the stake-to-profit ratio, but the market hold is better understood through implied probability: a −110/−110 market sums to ~104.76% implied probability, not 110%.
What win rate do I need to break even at −110? 52.38%. This follows directly from the implied probability math and is widely documented.
Are props priced worse than main lines? Often, yes. Hold varies significantly by prop type. Standard player props at −115/−115 carry about 6.5% hold. Some exotic prop categories carry 10–20%.
Does line shopping matter if the difference is only a few cents? Yes. A move from −110 to −105 changes your break-even rate from 52.38% to 51.22%. Repeated across hundreds of bets, that difference is meaningful.
Put it to use
See the vig embedded in real MLB prop markets alongside model-implied probabilities:
Continue learning: Implied Probability · Expected Value in Sports Betting · Line Shopping · Bankroll Management