Comparing Eras: How We Calculate Our Adjusted Team Ratings
Why are the adjusted team ratings important?
Because they normalize a team’s performance (for any sport) from league environmental factors that can either inflate or deflate its numbers.
That’s done with a model that uses advanced metrics and other factors on both sides of the ball to calculate how many points per 100 possessions (for basketball) or how many runs per nine innings (for baseball) or how many points per 10 drives (for football) better or worse teams are compared to the league-average club during that season, including the playoffs.
From this model, we’re able to create an adjusted offensive rating (AOR), adjusted defensive rating (ADR) and an overall adjusted team rating (ATR). Using the 2020-21 NBA season as an example, here’s a look at those in the chart below. Note that lower is better for defensive ratings in each sport.
Adjusted Team Ratings, 2020-21 Regular Season
| Team | AOR | Off. Rank | ADR | Def. Rank | ATR | Overall Rank |
|---|---|---|---|---|---|---|
| Utah Jazz | 5.66 | 4 | -3.27 | 4 | 8.92 | 1 |
| Phoenix Suns | 6.52 | 3 | 0.84 | 13 | 5.68 | 2 |
| Philadelphia 76ers | 2.01 | 10 | -3.42 | 3 | 5.43 | 3 |
| Los Angeles Clippers | 5.09 | 7 | -0.22 | 8 | 5.32 | 4 |
| Milwaukee Bucks | 5.42 | 5 | 0.47 | 10 | 4.95 | 5 |
| Denver Nuggets | 5.33 | 6 | 0.47 | 11 | 4.85 | 6 |
| Brooklyn Nets | 6.57 | 2 | 2.31 | 23 | 4.26 | 7 |
| Portland Trail Blazers | 6.92 | 1 | 3.36 | 27 | 3.56 | 8 |
| Los Angeles Lakers | -2.29 | 25 | -5.06 | 1 | 2.77 | 9 |
| New York Knicks | -0.91 | 21 | -3.53 | 2 | 2.62 | 10 |
| Atlanta Hawks | 4.11 | 9 | 1.76 | 21 | 2.35 | 11 |
| Dallas Mavericks | 4.34 | 8 | 2.03 | 22 | 2.30 | 12 |
| Golden State Warriors | 0.31 | 17 | -1.80 | 5 | 2.11 | 13 |
| Memphis Grizzlies | 0.11 | 18 | -1.12 | 6 | 1.23 | 14 |
| Miami Heat | 1.18 | 14 | 0.01 | 9 | 1.18 | 15 |
| Boston Celtics | 1.83 | 11 | 1.38 | 17 | 0.45 | 16 |
| Indiana Pacers | 1.00 | 15 | 0.81 | 12 | 0.19 | 17 |
| New Orleans Pelicans | 1.36 | 12 | 1.52 | 18 | -0.17 | 18 |
| Chicago Bulls | -0.98 | 22 | -0.79 | 7 | -0.19 | 19 |
| Washington Wizards | 0.33 | 16 | 1.24 | 16 | -0.91 | 20 |
| San Antonio Spurs | -0.60 | 20 | 0.94 | 14 | -1.54 | 21 |
| Toronto Raptors | -0.25 | 19 | 1.56 | 19 | -1.81 | 22 |
| Charlotte Hornets | -1.01 | 23 | 1.73 | 20 | -2.75 | 23 |
| Sacramento Kings | 1.25 | 13 | 4.81 | 30 | -3.56 | 24 |
| Minnesota Timberwolves | -1.48 | 24 | 2.43 | 24 | -3.91 | 25 |
| Detroit Pistons | -4.55 | 27 | 0.96 | 15 | -5.51 | 26 |
| Houston Rockets | -4.12 | 26 | 3.39 | 28 | -7.50 | 27 |
| Cleveland Cavaliers | -6.23 | 28 | 3.93 | 29 | -10.16 | 28 |
| Orlando Magic | -7.30 | 29 | 3.03 | 26 | -10.33 | 29 |
| Oklahoma City Thunder | -8.76 | 30 | 2.54 | 25 | -11.30 | 30 |
In this example, the Utah Jazz (52-20) reeled off 20 victories in 21 games during a red-hot stretch earlier in 2021 before managing to hold off the Phoenix Suns (51-21) for the league’s top overall record, but no one was really close to the Jazz in terms of overall adjusted team rating.
Now that didn’t mean the Larry O’Brien Trophy was guaranteed to head to Salt Lake City. In fact, past four teams that finished with the league’s best ATR did not win the championship after the Milwaukee Bucks beat the Suns in 2021. The 2019-20 Bucks (8.53), the 2018-19 Bucks (9.06) and the 2017-18 Houston Rockets (8.56) also fell short.
The Los Angeles Lakers limped into the playoffs in 2019-20 before winning 16 of 20 to capture the franchise’s 17th title and finish fourth in the ratings.
The 1995-96 Chicago Bulls, who set a league record at the time by going 72-10 before winning it all behind Michael Jordan, Scottie Pippen and Dennis Rodman, have the top ATR we’ve recorded in the NBA since the 1986-87 season at 14.14.
Keep in mind that the model is backward-facing, so it’s based on how well a team has played and not necessarily how well a team will play.
Data modeling by Matt Scott.