The Efficiency of the NBA Market
Of all major sports, the NBA has the most efficient betting market. This means the closing point spread is incredibly accurate at predicting the actual margin of victory. Why? It comes down to sample size and scoring frequency. In an NFL game, there might be 15 total scoring events. In an NBA game, there are often over 100.
High Possession Counts
With more possessions and higher scoring, the variance (luck) decreases significantly. The better team is much more likely to win a basketball game than a baseball or hockey game, simply because a lucky bounce has less impact on a game with 220 total points than a game with 5 total goals.
Algorithmic Oddsmaking
Modern sportsbooks use highly advanced machine learning models to set opening lines, taking into account player efficiency ratings, pace of play, and rest days. Once the opening line is published, syndicates and sharp bettors immediately wager millions of dollars to correct any inefficiencies. By tip-off, the point spread has been shaped by the absolute smartest money in the world, making it very difficult for the average bettor to beat without specialized tools.