Beat the Book - Calculate Your Edge
The vig (vigorish) is the sportsbook's commission built into the odds. It's how they guarantee profit regardless of the outcome.
Example: Standard -110/-110 odds have a 4.55% vig. This means the total implied probability is 104.55% instead of 100%.
Lower vig = Better value for you! Always shop for the best odds to minimize the vig you're paying.