Vig / Vigorish
Vig, or vigorish, is the margin built into sportsbook odds. See how 1.91 prices add up and how vig differs from overround and hold.
Vig, short for vigorish, is the sportsbook’s built-in price margin. You may also hear it called juice. It affects the price you need to beat; it does not guarantee that the sportsbook will make a fixed profit on every market.
A simple two-outcome example
Suppose both sides of a market are priced at decimal odds of 1.91. Each price implies a probability of about 52.36% because 1 divided by 1.91 is about 0.5236. Add the two implied probabilities and you get about 104.71%.
The amount above 100% is the market’s overround: about 4.71 percentage points in this example. It shows how the prices are set. It is not a promise that the book’s actual profit will equal 4.71% of every dollar wagered.
Vig, overround and hold are related, but different
Overround is calculated from the implied probabilities in a complete set of odds. Vig is the margin embedded in the price, often used as a casual name for the same pricing cost. Hold usually describes the share of stakes a sportsbook keeps over a period after results are settled.
Those measures can move differently. Odds change, bets may be unevenly distributed, and outcomes can produce a loss even when a market is priced above 100%. For that reason, an overround calculation describes the quoted market, not the operator’s final financial result.
What no-vig odds can and cannot tell you
You can remove the displayed overround proportionally by dividing each raw implied probability by the sum of all probabilities. With two equal 1.91 prices, that produces 50% for each side. This is a normalization method, not proof that each outcome has a true 50% chance.
It is useful for comparing prices on the same complete market. It cannot account for every pricing model, information advantage or difference between sportsbooks. Use the no-vig calculator with every outcome in the market, then read how overround is calculated.