Sports Betting
Vigorish
Vigorish is the bookmaker's fee or margin built into the odds on a wager, ensuring the house profits regardless of the outcome.
- Also called
- Vig, juice, house edge, cut, margin, take, under-juice, overround.1
- Applies to
- Fixed-odds sports betting, sportsbook betting, spread betting, and parimutuel betting.2
- Spread-betting example
- 9 cents per dollar wagered; winning bet pays 91 cents per dollar.5
- Key formula
- Bookmaker margin = (∑1/oⱼ) − 1, where oⱼ are decimal odds for each outcome.4
Key points
- Bookmakers set odds so implied probabilities exceed 100%, creating a built-in margin that is the house's expected profit if the book is balanced.1
- In spread betting, the vig is typically 9 cents per dollar wagered, with a 91-cent payout on a winning bet.5
- In parimutuel systems, the house take is deducted from the pool before winnings are distributed.3
How vig is built into odds
- Bookmaker calculates the true probability of each outcome.
- Converts those probabilities into decimal odds.
- Adjusts odds downward so the sum of implied probabilities exceeds 100%.
- The excess percentage is the vig — the bookmaker's guaranteed margin.
Where this term is used
Related terms
Sports betting
Vigorish betting
Explains how betting in markets that charge a vig affects long-term returns.
Sports betting
Parlay
A single bet linking multiple selections, where vig compounds across each leg.
Sports betting
Moneyline
A straight bet on which side wins, with odds that already include the vig.
Sports betting
Spread betting
A wager on the margin of victory, where vig is typically charged per dollar bet.
Sports betting
Moneyline betting
Betting on the outright winner, with vig factored into the odds.
Sports betting
Point spread
The handicap set by bookmakers to balance action, with vig added to both sides.
Sources
- Vigorish en.wikipedia.org Defines vigorish and provides the two-outcome formula.
- Sports betting en.wikipedia.org Confirms vigorish applies to sports betting.
- Parimutuel betting - Wikipedia en.wikipedia.org Explains how house take works in parimutuel systems.
- [2107.08827] Optimal sports betting strategies in practice - ar5iv ar5iv.labs.arxiv.org Provides the bookmaker-margin formula in normalized form.
- Identifying Inefficiencies in Sports Betting Markets arxiv.org Provides the spread-betting example of 9 cents vig per dollar.
Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.