In almost every NBA match, but also in most sports matches in general, one of the teams is considered to be the favorite, whereas the other is the underdog. For each particular game there’s a consensus on this issue among sportsbooks. The quote that you get for a victory of the favorite is usually in the minus (-) range, whereas you’ll get a plus (+) quote for the underdog.
As you probably know, American odds feature numbers above one hundred with either a plus or a minus sign. Odds with a plus sign tell you how much will $100 bet bring you if you get it right, whereas minus odds tell you how much you need to bet in order to win $100. For example if the odds are +150, that means that $100 will win you $150, and if the odds are -120, that means that you’ll need to bet $120 in order to win $100.

What are point spreads?

With point spread betting, the point is to eliminate the favorite/underdog difference. This number, the point spread is a presupposed point difference that the favorite is expected to gain, whereas the underdog is supposed to keep the score difference below that level. This difference is also given with + and – symbols for the respective team. The point spread for the favorite will have a minus sign and that would signify that the favorite is expected to win the match by more than the specified point spread.
For example if the point spread is -4.5, then the favorite would have to win with at least 5 point difference. Similarly, the underdog is supposed to either lose with less than 4.5 points, or get a draw, or win the game. We know that draws aren’t very common in NBA. Still, with the point spread eliminates this possibility, the match ends with either one team winning with more than 4.5 points, or not.
Now, we will give you an example of this, to makes things clearer. For example, let’s say that the Heat is playing against the Spurs and the latter team is the favorite. The bookies have judged that the Spurs should win by at least 6 points. Then when you look for this match under the point spread betting, you’ll see this- Miami Heat +5.5 at San Antonio Spurs -5.5. Practically, any loss with less than 5.5 points for the Heat will be considered a victory for that particular bet. Usually, it is considered that the aim of the introduction of the NBA point spread betting is to make the bet more even and the odds given for either of the two possible bets is -110, although it could be -115 at some sportsbooks.
However, it can be noted that different odds are given. For example, the sportsbook may set the point spread at 7.5 and give -130 odds for the Heat and, say, +120 for the Spurs. Sometimes the sportsbooks decide to introduce more different point spread bets. If we image the same match from the previous paragraph, we may have a 3.5, a 5.5, a 7.5, a 9.5 and an 11.5 bet. Sometimes you may even see a point spread where it is expected that the underdog will win by a certain amount of points.

Whole number point spreads

In addition to all this, the sportsbooks may decide to specify the point spread at a whole number, like 5, 7 or 8. In this case if the favorite wins by that specific number of points, no more and no less, the bet is considered a push and you’ll receive a certain amount of your original bet. And if both teams are considered to be evenly matched and the sportsbooks can’t set a favorite, then you get the same, or almost the same bets for both teams, but without a point spread. At certain books and for certain games you can bet on the difference that the favorite is going to have at a particular part of the game, like after the first quarter, on half-time or after the third quarter.