Bookmaker's interest - In order to guarantee a profit for the house, a bookie needs to create even action on both sides of a particular game. In a perfect world the bookie would have 50 percent of the handle come in on the underdog and 50 percent on the favorite. This ensures that the sports books are guaranteed a profit because of the 10 percent commission or "vigorish" charged on most sports wagers. This is why there is "movement" on the point spread. If one side on a game is being bet more heavily, the bookie must move the number in order to attract interest on the other side in order to balance action.
In most football games there is a favorite and an underdog. Very occasionally there are games where the two team are completely evenly matched, but for the most part one team is favored over the other to win. With point spreads, the idea is to create an even money proposition when betting on the game. So the favorite has to win by at least a certain number of points for a wager on them to be successful, and the underdog has to lose by no more than a certain number of points for a wager on them to be successful. The bigger the gap in quality between the two teams, the bigger the point spread.
Had you initially bet $100 on the Mavericks, you would walk away with a profit of $90.91. Now, if you bet on the Mavericks, you will see a profit of only $76.92. On the other side of the bet, an earlier bet on the Magic would have paid you $105. Now that same $100 bet will get you $125 if the Magic win the game. Ideally, this will entice more people to bet on the Magic and the action on the Mavericks to slow down.
Why is this important? If you’re only looking for a fun sweat, it does not matter at all. But, if you’re looking to be a winner and making money long-term is important, then this becomes critical. For those of you profit-minded bettors, make sure that you are only betting on the prop bets that require quite a bit of skill. These bets will be the ones that your knowledge, research, and expertise will help you win over the long run.
You may have heard the term “covering the spread” or the phrase “betting against the spread.” This means that if the favorite team wins an event with the point spread taken into account or that the underdog team wins with additional points, they have covered the spread. If the Packers win that game by more than 7 points, they have covered the spread.