What is Vig (Juice)?

The vig — short for vigorish, also called 'juice' — is the bookmaker's built-in commission, baked into the odds so that the implied probabilities of all outcomes in a market add up to more than 100%. That surplus over 100% is the operator's margin, the structural advantage that makes a sportsbook profitable on balanced action. Because the vig is embedded in every price rather than charged as a separate fee, many bettors underestimate how much it erodes returns. Worked example: a two-way market is priced at 1.91 on each side. Converting to implied probability, 1 ÷ 1.91 ≈ 52.4% per side, and the two sides sum to about 104.8%. The 4.8 percentage points above 100% are the vig. In practical terms, on a fair coin flip the true price is 2.00 each way; the book paying only 1.91 each way is keeping that margin. Over many bets, paying 1.91 for something worth 2.00 is a guaranteed long-run drag even if your selections are exactly 50/50. Why it matters: the vig is the hurdle every bettor must clear before showing a profit. At standard −110 pricing you must win about 52.4% of bets just to break even, not 50%. Lower-vig books (Pinnacle is the classic example) leave more value on the table and are favoured by sharp bettors. The common mistake is comparing only the headline odds on your chosen side while ignoring the total market margin. A book can look competitive on the favourite yet load the vig onto the other side. Always assess the full two-way (or multi-way) price. Reducing the margin via arbitrage across books, or simply line-shopping, directly improves results. Compare with implied probability, the house edge and arbitrage.