Vig is the house’s tax (and you pay it every time)
If you’ve ever wondered how sportsbooks make money when half the bets win and half lose, meet the answer: vig.
Vig (short for “vigorish,” also called “juice”) is the built-in fee the sportsbook charges by shading the odds. You don’t see it as a line item like “$2.50 service fee.” You see it as worse prices than “fair” odds.
Think of a sportsbook like a currency exchange booth at the airport. If the “real” exchange rate is 1.00, they’ll buy from you at 0.97 and sell to you at 1.03. That gap is their profit margin. Sportsbooks do the same thing with probabilities. They take a market that should add up to 100% and make it add up to more than 100%. That extra is your tax.
Why it matters: the vig changes your break-even rate (the win % you need just to not lose money). At -110 on a point spread, you need to win more than 50% to break even. You need 52.38%. That extra 2.38% is the tax showing up in your results.
Most beginners spend all their energy trying to “get to 55%.” Good instinct. But the faster path is often less glamorous: pay less tax. That means understanding vig, hold, and overround—then line shopping like your bankroll depends on it (because it does).
If you’re still getting comfortable with odds formats, read Decimal vs American Odds: Convert Fast (and Stop Mispricing Bets). You’ll use those conversions constantly when you start spotting vig in the wild.
Three terms you’ll hear nonstop: vig, overround, and hold
People toss these around like they’re the same thing. They’re related, but not identical.
Overround is the easiest to define: it’s how much the implied probabilities add up to over 100% in a market.
Example: a true 50/50 coin flip should be 50% + 50% = 100%. If a book prices it so the implied probabilities add to 104%, that market has a 4% overround.
Vig is the practical name bettors use for that overround/price shading. It’s the “tax” you pay via worse odds. When someone says “this book is dealing high vig,” they mean the overround is fat and your break-even point is higher.
Hold is the sportsbook’s profit margin in practice over a set of bets. In theory, higher overround tends to create higher hold, but hold also depends on what bettors actually bet and how outcomes land.
- Overround = what the odds imply (built into the screen)
- Vig = the juice/tax (what you feel as a bettor)
- Hold = what the book keeps (what the sportsbook reports)
Here’s a clean way to remember it:
Overround is the recipe, vig is the taste, hold is the calories.
As a bettor, you can’t control the hold. You can control the overround you choose to bet into by shopping lines and picking lower-vig markets.
How to spot overround from any odds screen (in 20 seconds)
You don’t need a spreadsheet. You need one habit: convert odds to implied probability, then add them up.
Step 1: Convert each side to implied probability.
For decimal odds: implied probability = 1 / decimal odds.
For American odds:
- If the line is negative (e.g., -110): implied probability = |odds| / (|odds| + 100)
- If the line is positive (e.g., +120): implied probability = 100 / (odds + 100)
Step 2: Add probabilities across all outcomes.
If it’s a two-way market (Team A vs Team B, no draw), you add both sides. If it’s a 3-way soccer market (Home/Draw/Away), add all three. If it’s an outright with 20 golfers, add all 20.
Step 3: Subtract 100%.
The amount over 100% is the overround.
Quick example with a standard spread:
Bears -3 (-110)
Packers +3 (-110)
Implied probability for -110:
110 / (110 + 100) = 110 / 210 = 0.5238 = 52.38%
Add both sides:
52.38% + 52.38% = 104.76%
Overround = 104.76% - 100% = 4.76%
That 4.76% is the “tax” baked into this market. It doesn’t mean the book will hold exactly 4.76% on that game, but it tells you what you’re paying to play.
If you want to practice these conversions without frying your brain, the Betting Assistant is perfect for drilling implied probability and break-even math until it’s automatic.
The simple example that explains everything (and why -110 isn’t “close to even”)
Let’s use one market and walk it all the way through. Same game, two different sportsbooks.
Book A: -110 / -110 (classic)
Book B: -105 / -105 (reduced juice)
Both books are offering the same spread. You’re not “handicapping better” by choosing Book B. You’re just paying less damn tax.
Break-even rate is the win % you need so your expected profit is zero.
For American odds, break-even is:
- For -110: 110 / (110 + 100) = 52.38%
- For -105: 105 / (105 + 100) = 51.22%
That looks small. It isn’t.
Say you make 1,000 spread bets at $100 risk each.
If you win 52% (a decent recreational run):
- At -110, you’re below break-even (52% vs 52.38%). You lose money long term.
- At -105, you’re above break-even (52% vs 51.22%). You win money long term.
Let’s put dollars on it.
At -110, a $100 bet wins $90.91 profit.
Wins: 520 × $90.91 = $47,272
Losses: 480 × $100 = $48,000
Net: -$728
At -105, a $100 bet wins $95.24 profit.
Wins: 520 × $95.24 = $49,285
Losses: 480 × $100 = $48,000
Net: +$1,285
Same picks. Same win rate. Just a different price. That’s a $2,013 swing over 1,000 bets because you refused to overpay.
This is why “I hit 52% and still lost” happens all the time. It’s not bad luck. It’s the vig.
Hold vs overround: why your sportsbook can hold more (or less) than the vig
Overround lives in the odds screen. Hold lives in the sportsbook’s actual results. They rhyme, but they’re not married.
Here’s how a book can have a 4.76% overround on a spread (-110/-110) and still hold way more than that on a Sunday slate:
- One-sided betting: If everyone piles into the Chiefs -3 and they don’t cover, the book cleans up.
- Parlays: Parlays stack vig and add correlation mistakes bettors don’t understand. Books love them. (Yes, most parlays are sucker bets.)
- Props and niche markets: Many props carry bigger overrounds than main lines, and limits are lower, so prices don’t get sharpened as quickly.
- Timing: Early openers might be softer (lower “effective tax” if you beat the move). Late lines can be efficient but still expensive.
And the reverse happens too. A book can deal higher overround and still have a low hold if bettors get lucky or if the book takes balanced action and outcomes split.
As a bettor, don’t obsess over a book’s reported hold. Obsess over what you can measure instantly: the price you’re paying right now.
This connects directly to CLV (closing line value). If you consistently beat the closing number, you’re usually getting good prices and paying less vig than the market consensus. If you’ve never tracked that, start here: Why CLV Beats Win Rate (and How to Track It Daily).
Line shopping: the easiest edge you’ll ever find (and people still ignore it)
Line shopping means checking multiple sportsbooks and taking the best available price for the bet you already want.
That’s it. No magic models. No secret system. Just not donating extra vig.
Recreational bettors get crushed here because they fall in love with one app. They deposit, they bet, they repeat. The book quietly charges them a worse exchange rate forever.
What line shopping looks like in real life:
- You want Lakers +4.5. One book has -110, another has -105. You take -105.
- You want a soccer favorite at -150. Another book offers -140. You take -140 (that’s a meaningful difference).
- You want Over 47.5 at -110. Another book has Over 48 at +100. You decide which is better for your bet type, but you make the decision with math, not vibes.
Even when the odds look “basically the same,” your bankroll feels it over volume. If you bet 500–2,000 times a year (very normal if you play sides, totals, and props), tiny price differences become the difference between a profitable year and a losing one.
Tools can help you see this in one glance. The Edge Finder is useful for comparing how different books price the same market and showing how a lower-vig number can swing expected value from negative to positive without you changing your opinion on the game.
And if you’re trying to beat fast-moving markets, price comparisons pair nicely with alerts. This post explains why speed matters: Set Price Alerts That Beat Steam by 30 Seconds.
Quick rules: where vig hides the most (and where you should be picky)
Not all markets charge the same tax. Sportsbooks know what bettors love, and they price accordingly.
Here are some practical rules you can use immediately:
- Main spreads and totals (NFL/NBA/NHL): usually the lowest vig and most efficient. If you’re learning, start here. If you’re paying -115/-115 on a major spread, you’re overpaying unless there’s a reason.
- Moneylines in low-draw sports (NBA/NHL): can be reasonable, but favorites often carry more hidden tax than you think. Always convert to implied probability and check the overround.
- Player props: commonly higher overround. If you’re not line shopping props, you’re lighting EV on fire.
- Same-game parlays: the book has more control over pricing, especially with correlated legs. Fun? Sure. Efficient? Hell no, not most of the time. If you insist on playing them, be extra strict on price.
- Alternative lines (alt spreads/totals): can be massively overpriced. Some are fine, many are pure convenience fees.
Also: vig isn’t only about the number next to the team. It hides in the half-points too. Paying -120 to get from +3 to +3.5 in the NFL might be a good deal or a terrible one depending on the key number value. If you want a clean example of how hooks matter, read Spread Traps in NCAAB: Why +2.5 Can Be Worse Than +3.
If you want more beginner-friendly education like this, the education hub lives at /blogs/education/.
Responsible gambling note: Treat betting like a paid hobby, not a bill-paying plan. If the vig math is stressing you out, take a break and come back when you’re clear-headed.
