The book's edge
Vig (juice)
How to calculate the vig from any two prices
Convert both sides to implied probability and add them up. A margin-free market sums to exactly 100%; a real one sums higher, and the excess is the vig. At −110 each side implies 110 ÷ 210 = 52.38%, so the market sums to 104.76%.
That 4.76 points of excess is the overround. Expressed as a share of everything staked — 4.76 ÷ 104.76 — it comes to 4.55%, which is the number that actually matters to you. The two get used interchangeably, but they aren't the same figure, and the gap widens as the margin grows.
This works on any two-way market, not just −110/−110. A −140/+120 moneyline implies 58.33% + 45.45% = 103.79%, an overround of 3.79 points and a hold of 3.65% — a cheaper market than the standard spread, which is not obvious from looking at it.
What it actually costs you over a season
Take a bettor who wins exactly half their bets at −110. Over 100 bets risking $100 each, they collect 50 × $90.91 = $4,545 and lose 50 × $100 = $5,000. Net: −$455 on $10,000 staked, or −4.55%. That is the vig, and it arrives whether or not you were right about anything.
Scale it up: $50,000 pushed through the window across a season costs about $2,270 in margin alone. That is the number a break-even handicapper has to overcome before their opinion earns a cent.
The vig is not the same in every sport
The standard −110 is a convention for spreads and totals, not a law. We measured the real consensus margin across six sports from our own captured odds — 315 games and 3,437 priced sides — and it ranged from 4.54% to 5.98%.
The practical takeaway is in the last column: taking the best available price instead of the market consensus removed roughly half the margin in most sports. Boxing was the exception, and it was also the most expensive market to begin with.
| Sport | Games | Consensus | Best available | Removed |
|---|---|---|---|---|
| MLB | 150 | 4.60% | 2.28% | 50% |
| Boxing | 62 | 5.98% | 4.26% | 29% |
| UFC / MMA | 49 | 4.75% | 2.02% | 57% |
| NCAAF | 27 | 4.54% | 2.36% | 48% |
| WNBA | 19 | 4.78% | 2.13% | 55% |
| CFL | 8 | 4.55% | 2.14% | 53% |
Sample sizes vary; MLB, boxing and UFC are solid, CFL is thin. The NFL was measured and excluded — its only captured prices were low-limit June offseason lines. Full methodology in the study.
Source: What the vig actually costs, by sport — 315 games, 3,437 priced sides, June–July 2026.
The common mistake: treating the vig as a fee on your winnings
The vig isn't deducted when you win — it's priced into the odds before you bet, which is why it costs you on the bets you lose too. A −110 line already pays you less than a fair coin flip would. That's also why shopping for −105 instead of −110 is not a rounding difference: over a season it is a larger swing than most people's handicapping edge.
Related terms
Common questions
- What is the vig in betting?
- The vig (vigorish, juice, or the hold) is the sportsbook's built-in commission, priced into the odds rather than charged separately. At the standard −110 on both sides you risk $110 to win $100, which works out to about a 4.5% margin and means you need to win 52.4% of your bets just to break even.
- How do you calculate the vig from odds?
- Convert both sides to implied probability and add them. A fair market sums to 100%; the excess is the vig. Two sides at −110 imply 52.38% each and sum to 104.76% — an overround of 4.76 points, which is a hold of about 4.55% of everything staked.
- Which sport has the highest vig?
- In our own measurements across 315 games, boxing was the most expensive at a 5.98% consensus margin — more than a point above every other market we measured. It was also the least improvable by line shopping: the best available prices still left 4.26%.
- How do you pay less vig?
- Line shopping is the only reliable method: take the best available price on every bet instead of the first one you see. In our measurements that removed 48–57% of the margin in most sports. Reduced-juice books and avoiding parlays, which compound the margin on every leg, help too.
See these numbers on your own bets
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