The point spread is one of the most popular bet types for the NBA. Sportsbooks install a spread on each game, and you need to factor it into your handicapping. The spread is basically like a margin of victory. The team expected to win will be favored by a certain amount of points. If you bet on that team minus the spread, it will need to win by more than that number to cover the spread. If you go with the underdog plus the spread, it needs to keep the margin under the number or win the game outright.