NBA spreads are a popular betting format that levels the playing field between two teams by assigning a point differential. The favored team must win by more than the spread for a bet on them to pay off, while the underdog can either win outright or lose by fewer points than the spread. This system adds excitement to games, as bettors not only root for their chosen team to win but also for the margin of victory. Understanding spreads is crucial for successful sports betting, as they reflect team performance, injuries, and other factors influencing game outcomes.