Juice / Vigorish (Vig)

Juice — also called vig, vigorish, or simply the bookmaker’s margin — is the cut a bookmaker takes for offering a market at all. It isn’t a separate fee added to your bet slip; it’s baked directly into the odds themselves. Every price you see has been shaded slightly against you compared to the “true” chance of that outcome happening, and the gap between the two is how the bookmaker turns a profit regardless of who wins.

The cleanest way to see it is to convert odds into implied probability. Decimal odds convert with a simple formula: 1 ÷ odds = implied probability. If a market were perfectly fair, the implied probabilities of every possible outcome would sum to exactly 100%. In practice they always sum to something higher — 104%, 106%, sometimes 110%+ in obscure or live markets. That surplus above 100% is the juice, and it represents the bookmaker’s theoretical edge if it took equal, balanced action on every outcome.

Juice matters because it’s the tax you pay just for playing, separate from whether your prediction is any good. A bettor who correctly picks winners 55% of the time can still lose money long-term if the juice on the markets they bet is high enough to erase that edge. This is also why shopping for the best price across bookmakers, and why some markets (main lines, high-liquidity leagues) carry far thinner juice than niche ones (obscure lower-league specials, same-game parlays, in-play props), is one of the few genuinely controllable edges a bettor has.

Example

Take an Eredivisie match, Ajax vs Feyenoord, priced by a bookmaker as a straight 1X2 market:

• Ajax to win: 2.05
• Draw: 3.60
• Feyenoord to win: 3.50

Convert each to implied probability using 1 ÷ odds:

• Ajax: 1 ÷ 2.05 = 48.78%
• Draw: 1 ÷ 3.60 = 27.78%
• Feyenoord: 1 ÷ 3.50 = 28.57%

Add them up: 48.78% + 27.78% + 28.57% = 105.13%.

A fair, no-margin market sums to exactly 100%, so this book has built in 5.13 percentage points of juice. To find the “fair” odds the bookmaker believes reflect the true chances, strip the margin out by dividing each outcome’s implied probability by the total (1.0513):

• Ajax fair probability: 48.78% ÷ 105.13% = 46.40% → fair odds 2.16
• Draw fair probability: 27.78% ÷ 105.13% = 26.42% → fair odds 3.79
• Feyenoord fair probability: 28.57% ÷ 105.13% = 27.18% → fair odds 3.68

Notice every single price the bookmaker actually offers (2.05, 3.60, 3.50) is shorter than its fair equivalent (2.16, 3.79, 3.68). That gap, repeated across every outcome, is where the 5.13% edge lives. If the bookmaker took bets in exactly the proportions implied by those probabilities — say €4,878 on Ajax, €2,778 on the draw, and €2,857 on Feyenoord from a €10,513 total pool — it would pay out roughly €10,000 to the winning side no matter which outcome hit, banking the €513 difference as pure margin.

Key Points

• Sum the implied probabilities to spot the juice: Convert every price in a market with 1 ÷ odds and add them together. Anything above 100% is margin; the further above, the worse the market is for you.
• Lower juice markets favour sharper bettors: Heavily bet markets like English Premier League or Champions League match odds often run 4-6% margin, while niche markets like corner-count specials or lower-tier tennis qualifiers can run 10%+. Save your volume for the tighter markets when possible.
• Juice compounds across legs: A five-leg accumulator built from bets each carrying 5% margin doesn’t cost you 5% overall — the margins multiply, so a bet slip that looks generous leg-by-leg can carry a brutal combined edge against you.
• Compare the same market across bookmakers: Because juice is set independently by each operator, the same Ajax vs Feyenoord match might carry 5.13% margin at one book and 3.80% at another. Price comparison sites exist largely to help bettors find the thinnest juice on a given match.
• A winning record isn’t proof of skill until juice is accounted for: If your hit rate only clears break-even after adjusting for a market’s margin, you don’t yet have a real edge — you’ve matched the bookmaker’s own model.
• Juice, not luck, is the house’s real long-run engine: Bookmakers don’t need to predict outcomes perfectly; balanced two-sided action at a fixed margin produces steady profit on volume alone, which is why margin management matters more to them than any single result.