Which group is your best of all time? To answer that question with much more rigor than it is typically debated in sports bars, in 2015 I ranked every team since minutes played were tracked in 1951-52 (sorry to the 1949-50 Minneapolis Lakers) based on their performance in the regular season and playoffs.
Three years after, it’s time for an update using a brand new No. 1, and several other newcomers to the record as a result of the Cleveland Cavaliers and Golden State Warriors dominating the competition in their respective conferences.
For champions, I took the average of the point differential during the regular season and their point differential in the playoffs plus the point differential of their opponents. That tells us just how many points per game better than an average team each winner was, giving equal weight to the postseason as the regular time to reward the most important games.
For non-champions, the starting point is exactly the same, but their playoff differential was also adjusted by effectively giving them a five-point loss for each game they came up short of this title. That has little effect on teams like the 2012-13 San Antonio Spurs, who lost in Game 7 of the Finals, but it harshly penalizes teams that wrapped up large victory margins early in the playoffs before falling short in the conference finals.
The adjustment deals with quality of play. It’s not surprising that some of the greatest single-season team performances in NBA history came from the early 1970s, once the league had expanded rapidly and also battled the ABA for incoming draft picks. The redistribution of talent enabled stars to glow even more brightly. For every season, I measured how players saw their minutes per game increase or decrease the following season as compared to what we’d expect given their age. More minutes indicates that a weaker league, while fewer moments suggests one that has gotten stronger.
Each year is ranked relative to 2017-18, from a high of 21 percent stronger in 1965-66, the previous year that the NBA had only nine teams, to a low of 10 percent poorer in 2004-05, the last time the league enlarged. That adjustment is multiplied by the group’s average regular-season and playoff scores to provide a last score greater than an average team this year.