Best Teams Ever

This page is dedicated to ranking the best offenses, defenses, and overall teams throughout NBA history. Criteria for offenses and defenses: I looked at regular season rOrtg, or how much ahead of the league in that year(s) the team was. So if team x had an offensive rating of 105 and the league had an average offensive rating of 100, that team is +5 for that year. Generally, anything over +6 is historic for offense, and anything over +5 is historic for defenses. The regular season gives the largest sample size and confidence interval. However, the playoffs matter. I looked at the aOrtg meaning the offensive rating adjusted for opponent. So if team y has an offensive rating of 120 in a series against team A who had a defensive rating of 113 in the regular season, team y would have an aOrtg of +13 for that series. Teams generally had to make at least round 2 for multiple years to qualify for the multi-year lists.

The same logic is applied for defense. Please note the Bill Russell Celtics teams noted at the bottom of the defense table. These are some of the best regular season defenses we have on record. However, due to typically playing only 2 playoff series each year and the lack of data, I’m not able to accurately portray how good their defense was in the playoffs, so they have their own separate category.

For the best overall teams, it’s different. It’s about looking at their total dominance, both sides of the ball. For this I looked at the regular season and playoffs. The criteria used were regular season point differential adjusted for pace (per100 is used to adjust for eras). I also looked at the post season adjusted point differential (per100 adjusted to the opponents they played). You will see this in Post season SRS, and Post season weighted SRS. The weighted factor weighs the later rounds more. This avoids weighing first round beat downs the same as finals competition vs high quality opponents. I also wanted to look at the actual W/L in the post season. Point differential gives a broader picture of how dominant a team is, but there's something to be said about losing as few games as possible during a title run. Using these three criteria, I got a model score and used some context and mental curving to rank the top 20 (about ¼ of all champions). The remainder of the teams just got a quartile score, as it’s not really feasible for me to argue that some team is 39th best vs 43rd best. They are all in a similar range. Again I want to touch on the Russell Celtics. How could I possibly have the teams that won 11 out of 13 titles all towards the bottom? This is the most dominant dynasty the league has ever seen, right? Well, in some sense yes, but when you look year by year, there were no truly dominant seasons. Part of this is due to having fewer teams so there is less room for margin between them. But most of it is that these weren’t dominant title teams. They were largely even with their opponents and nearly every year, Bill Russell came in with some amazingly clutch game 7 where they won by 2 points. If I’m thinking about the greatest teams of all time, they are running rough shot through the rest of the league. This is what we saw with the 2017 Warriors, the 2001 Lakers, 1996 Bulls, etc, etc. If you’re barely squeaking out wins, it might be a sign of late game heroics by an amazing player, but it’s not indicative of a titanic juggernaut of a basketball team. This is partly why the 2025 Thunder, who posted an insane regular season point differential, but were taken to 7 games twice, aren’t as high as their SRS would suggest.

For the 2 and 3 year samples, it gets even shakier. There are some teams that only won one title ranked ahead of others who won 2, which some people would find insane. How can you rank 1 championship over 2? I’m not trying to diminish the back to back title runs, I’m trying to evaluate the quality of the team. And sometimes, teams with the best quality over a 3 year span only win one title. Maybe they played a more difficult opponent, or had some string of exceptionally bad luck compared to the back to back team. Taking all this into account, I ranked the 2 and 3 year stretches as well.

-M