Spread bets are a bet on a team to win or lose, after a spread handicap is applied to the final score. 

A spread is a handicap applied to a match for betting purposes. The favourite is always indicated by a minus sign (e.g. -10.5) and the underdog by a plus sign (e.g. +10.5).

For spread betting purposes, the spread is the number of points added to or subtracted from a team’s final score at the end of the match. 

NBA Example: If you place a bet on the Raptors -10.5 to beat the Warriors +10.5, your bet would win if the Raptors won by 11 or more points.

If the Raptors beat the Warriors 114-110, your bet on Raptors -10.5 would lose because the Raptors only won the game by 4 points. After the spread handicap of -10.5 is applied to the final score, the Raptors would have "lost" the game 103.5 - 110.