Juice

Juice (also called Vig or Overround) refers to the commission or margin that a bookmaker builds into the odds to ensure a profit regardless of the outcome.

For example, in a 50/50 market, fair odds would be 2.00 (-100 in American odds), but a bookmaker might offer 1.91 (-110) instead. The difference represents the juice, which ensures the bookmaker profits over time. Lower juice means better value for bettors.