Defensive Rating Calculator
Our basketball calculator computes defensive rating instantly. Get accurate stats with historical comparisons and benchmarks.
Defensive Rating Calculator
Calculator
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Formula: DRtg = (Opponent Points / Team Possessions) x 100
Worked example — Defensive Rating: 107.1 | Classification: Good
Formula
DRtg = (Opponent Points / Team Possessions) x 100
Defensive Rating estimates points allowed per 100 possessions. Lower values indicate better defense. Individual adjustments factor in steals, blocks, and defensive rebounds.
Worked Examples
Example 1: Team Defensive Rating Calculation
Problem:A team allows 105 points while having 98 possessions in a game. What is their defensive rating?
Solution:Defensive Rating = (Opponent Points / Team Possessions) * 100 DRtg = (105 / 98) * 100 DRtg = 1.0714 * 100 DRtg = 107.1 points per 100 possessions
Result:Defensive Rating: 107.1 | Classification: Good
Example 2: Player Defensive Impact Assessment
Problem:A player plays 32 minutes out of 240 team minutes, records 1.5 steals, 0.8 blocks, and 5.2 defensive rebounds per game with team DRtg of 107.1.
Solution:Minutes Share = 32 / 240 = 13.3% Player Possessions = 98 * 0.133 = 13.1 Defensive Stops Estimate = 1.5 + (0.8 * 0.7) + (5.2 * 0.3) = 1.5 + 0.56 + 1.56 = 3.62 Stop Percentage = (3.62 / 13.1) * 100 = 27.6% Adjusted Player DRtg = 107.1 - (3.62 * 1.2) = 102.8
Result:Player DRtg: 102.8 | Stops: 3.6 | Rating: Excellent
Frequently Asked Questions
What is Defensive Rating in basketball and how is it calculated?
Defensive Rating (DRtg) is an advanced basketball statistic that estimates how many points a player or team allows per 100 possessions. It was popularized by basketball analyst Dean Oliver in his book Basketball on Paper. The basic team formula is straightforward: Team DRtg = (Opponent Points / Team Possessions) * 100. Individual defensive rating is more complex, incorporating steals, blocks, defensive rebounds, and other factors to estimate a single player contribution to team defense. A lower defensive rating indicates better defense, with elite NBA defenders typically posting ratings below 105 points per 100 possessions.
What is a good Defensive Rating in the NBA and how do top defenders compare?
In the modern NBA, a team defensive rating below 108 is considered good, below 105 is excellent, and below 102 is elite. For individual players, context matters enormously because individual defense is difficult to isolate statistically. Historically elite defenders like Ben Wallace, Tim Duncan, and Rudy Gobert have posted individual defensive ratings in the 95 to 100 range during their peak seasons. The league average defensive rating has fluctuated between 108 and 112 over the past decade. Teams that consistently rank in the top five defensively tend to be serious championship contenders regardless of era.
How do possessions affect Defensive Rating and how are possessions estimated?
Possessions are the fundamental denominator in defensive rating calculations and are estimated using the formula: Possessions = FGA + 0.44 * FTA - ORB + TOV. This formula accounts for field goal attempts, free throw attempts (weighted at 0.44 to estimate possessions ending in free throws), offensive rebounds (which extend possessions rather than creating new ones), and turnovers. The pace of play directly impacts raw point totals but not defensive rating since it normalizes to 100 possessions. A team allowing 100 points in 95 possessions (DRtg 105.3) is actually worse defensively than one allowing 110 points in 108 possessions (DRtg 101.9).
What are the limitations of Defensive Rating as a basketball metric?
Defensive Rating has several important limitations that analysts should understand. Individual defensive rating heavily depends on team context because defense is inherently collaborative. A mediocre defender on a great defensive team will have a better individual DRtg than a good defender on a poor defensive team. The metric also cannot capture important defensive contributions like deterring shots, forcing tough looks, effective communication, and help defense positioning. On-off court differential data can supplement DRtg but requires large sample sizes to be reliable. Advanced metrics like RAPTOR and EPM attempt to address some of these limitations using tracking data.
How does Defensive Rating differ from Defensive Win Shares and other defensive metrics?
Defensive Rating measures points allowed per 100 possessions, while Defensive Win Shares (DWS) attempts to translate defensive performance into estimated wins contributed. DWS uses defensive rating as an input but adds context about playing time, league averages, and marginal value. Other defensive metrics include Defensive Box Plus-Minus (DBPM), which uses box score stats to estimate defensive impact relative to league average, and newer tracking-based metrics like Defensive RAPTOR and Defensive EPM that incorporate spatial tracking data. Each metric captures different aspects of defense, and analysts typically use multiple metrics together to form a comprehensive picture of defensive ability.
How does Net Rating relate to Defensive Rating?
Net Rating is simply Offensive Rating minus Defensive Rating, both measured per 100 possessions, so it reads as points of margin per 100 possessions. A team scoring 114 and allowing 107 carries a plus 7.0 net rating. Because the two components share a possession denominator, they can be added and subtracted cleanly, which is exactly why analysts moved away from per-game point differential. Net rating also travels between lineups: a five-man unit's net rating tells you what that group does to the scoreboard.
Which of the Four Factors moves a Defensive Rating the most?
Dean Oliver's Four Factors split a possession into four things a defense can control: the opponent's effective field goal percentage, their turnover rate, their offensive rebound rate, and their free throw rate. Opponent eFG% carries by far the largest share, because most possessions simply end in a shot, and every percentage point of shooting efficiency converts directly into points per possession. Forcing turnovers is next, since a live-ball steal ends a possession with zero points and often starts a transition chance the other way.
Why do both teams end a game with almost the same possession count?
Possessions alternate. Every time one team's possession ends the other begins, so over a full game the two counts can differ only by a possession or two depending on who had the ball at the start and end of each period. That symmetry is what makes the metric coherent: your defensive rating uses the same denominator as your opponent's offensive rating, and pace cancels out of both. It also means a fast team cannot be penalised for allowing more raw points.
What is a defensive stop and how is stop percentage read?
A stop, in Dean Oliver's framework, is a defensive possession that ends without the opponent scoring, with credit assigned to whoever forced it. Stop percentage is stops divided by the possessions a player was on the floor to defend. This page approximates stops from steals, blocks and defensive rebounds with declining weights, because a steal ends a possession outright, a block often does not, and a defensive rebound closes out a possession someone else's contest created.
How does opponent quality distort a defensive rating?
Raw DRtg makes no schedule adjustment, so it partly measures who you played. A stretch against top-five offenses inflates the number without any drop in effort or scheme, and a run of games against rebuilding teams flatters it. Home and away splits push the same way, since scoring efficiency is generally higher at home. Compare a team's rating to the league average over the same window, or use a schedule-adjusted rating, before concluding that a defense has actually changed.
References
Reviewed for accuracy by Sher, Sports Science & Nutrition Specialist · Editorial policy
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