How to Use NBA Team Stats to Find Betting Value — Offensive and Defensive Ratings Explained
If you want to bet on the NBA seriously, you need to understand team ratings. Not points per game — ratings.
Points per game vs ratings
Points per game is the most obvious stat but the least useful for betting. It doesn't account for pace.
A team that plays fast will score more points simply because they have more possessions per game. A team that plays slow will score fewer. Comparing raw points per game between a fast team and a slow team tells you almost nothing.
Ratings fix this by normalising everything to 100 possessions.
Offensive rating
Offensive rating measures how many points a team scores per 100 possessions. A rating of 118 means the team scores 118 points for every 100 possessions they have.
The NBA average is typically around 113-115. Teams above 118 are elite offences. Teams below 110 are struggling.
Defensive rating
Defensive rating measures how many points a team allows per 100 possessions. Lower is better. An elite defence allows around 108-110 per 100 possessions. A poor defence allows 117 or more.
Net rating
Net rating is simply offensive rating minus defensive rating. A team with a +8 net rating is scoring 8 more points per 100 possessions than they're allowing. This is the single best predictor of a team's true quality — more reliable than win-loss record, points per game or any other single stat.
How a projection model uses ratings
The HMJOROTips NBA model uses a simplified version of this logic. For each game it takes the away team's offensive PPG and compares it against the home team's defensive PPG to project how many points the away team will score. It does the same in reverse for the home team.
The projected scores are combined to give a projected total and the difference gives the projected spread.
When this projection differs significantly from the bookmaker's line, that's where the value lies. If the model projects a combined total of 224 and the bookmaker has the line at 215.5, there's a meaningful edge on the over.
Where to find the data
The best free sources for NBA team ratings are Basketball Reference and NBA.com/stats. Both publish offensive and defensive ratings updated after every game.
For the HMJOROTips model the data is imported automatically from teamrankings.com which publishes PPG, opponent PPG, home/away splits and last 3 game averages — all the inputs the model needs to run projections daily.
Limitations to be aware of
Team ratings are averages. They don't account for specific lineup combinations, injuries, rest, or playoff adjustments. A team's defensive rating against guards is different to their defensive rating against centres.
The model is most accurate early in a series when both teams are playing to their averages. By Games 5, 6 and 7 the coaching adjustments have been made and the averages matter less than recent form and specific matchup trends.
Use the ratings as a starting point. Layer in the context — injuries, rest, home court, series momentum — and you'll have a sharper picture than most casual bettors ever will.
