Vigorish

Vigorish, or simply the vig, also known as juice, the cut or the take, is the amount charged by a bookmaker, or bookie, for his services. In the United States it also means the interest on a shark's loan. The term is Yiddish slang originating from the Russian word for winnings, выигрыш vyigrysh. Bookmakers use this practice to make money on their wagers regardless of the outcome. To minimize their risk, bookmakers do not want to have an interest in either side winning in a given sporting event. They are interested, instead, in getting equal betting on both outcomes of the event. In this way, the bookmaker minimizes his risk and always collects a small commission from the vigorish. The bookmaker will normally adjust the odds or the line, to attract equal action on each side of an event.

The concept is also sometimes referred to as the overround, although this is technically different, being the percentage the event book is above 100% whereas the vigorish is the bookmaker's percentage profit on the total stakes made on the event. For example, 20% overround is vigorish of 162⁄₃%. The connecting formulae are and where o is the overround.

It is simplest to assume that vigorish is factored in proportionally to the true odds, although this need not be the case. Under proportional vigorish, a moneyline odds bet listed at −100 vs. −100 without vigorish (fair odds) could become −110 vs. −110 with vigorish factored in. Under disproportional vigorish, it could become −120 vs. +100.