The total amount of money placed on the account in the game.The most popular use of the term is the Super Bowl, which always has one of the biggest crowds of the year. Sportsbooks often keep track of the number of bets for a particular event so they can compare it with previous years, which is the case with the Super Bowl.
Sportsbooks can also use the handle to help set betting lines. This is because if a particular game or side is getting a lot of attention at the same time, it may need to change something. If this happens, professional bettors are likely to join forces and bet on a particular side because they have noticed something strange about the original odds.