In sports betting Over 40.5 Points is an example of a total market you might see when betting on American Football. When betting on the Over market you need the total points of a game to exceed 40.5 for your bet to win.
if you bet on Team B, you need them to win by more than 22.5 points for you to cover your bet. That means they need to win the game by 23 points or more. If you bet on Team A, that means they can lose by 22 points or less, or win the game, and you still win your bet.