This article was updated after Wednesday's games.
With the Golden State Warriors knocking the 1995-96 Chicago Bulls from the record books by winning their 73rd game in Wednesday's season finale against the Memphis Grizzlies, the question of Warriors vs. Bulls is on everybody's mind.
Which one is the greatest team of all time? We have an answer.
Without the benefit of a time machine, there's no way to definitively settle the argument. But we can get closer to an objective answer by comparing two factors: how the two teams performed relative to the rest of the league, and how the league as a whole has evolved in the past two decades.
Answering the first question is fairly easy. Despite Golden State's chance at the superior record, Chicago was actually more dominant in 1995-96, beating opponents by an average of 12.2 points per game. Because they've relied on pulling out close games with strong clutch play, the Warriors' margin of victory is a relatively less impressive 10.6 points per game.
Figuring out how to adjust for league quality is much trickier, and more interesting as far as what it says about the NBA now as compared to two decades ago.
The NBA's growing player pool
The Bulls won 72 games not only in an expansion year, but at the conclusion of a stretch where the league grew quickly from 23 teams in 1987-88 to 29 by 1995-96. Since then, the NBA has added only one expansion team (Charlotte, in 2004-05) in the last 20 seasons.
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Meanwhile, the pool of players from which NBA teams can choose has grown rapidly. While Chicago benefited from the contributions of international rotation players Toni Kukoc, Luc Longley and Bill Wennington, such imports were relatively rare two decades ago.
In 1995-96, only six percent of the league's minutes were played by players raised abroad. That rate has jumped to 20.4 percent this season, narrowly surpassing last season's 20.3 percent to set another NBA record.
To estimate the size of the NBA's player pool, I've divided the size of the U.S. population by the percentage of NBA minutes played by American players. This suggests there are now about 400 million people available to the NBA, as compared to around 280 million in 1995-96.
Kevin Pelton
Obviously these estimates aren't to be taken literally, since they include women, children and men far past basketball retirement age. But their relative size is meaningful. There are now far more potential NBA players per professional team than at any point since the ABA emerged as a rival league in 1967.
Estimating quality of play
Naturally, more than just the number of available players goes into league quality of play. Factors like injuries, retirements and ebbs and flows of talent can also make a difference.
When I was creating my championships added metric to evaluate NBA players historically, I developed an estimate of NBA quality by looking at how returning players saw their minutes per game change from one year to the next. Increased playing time suggests a less competitive league, while an improving NBA means existing players see their minutes per game decrease.
That yielded the following estimates of quality of play over time relative to the 2015-16 season, which show steady improvement over time.
Kevin Pelton
What's interesting is how well the two measures match up. Since the league caught up with the effects of the ABA merger, changes in quality of play can largely be explained by expansion and the growth of the player pool. (The 2015-16 season, naturally, is in the top right.)
Kevin Pelton
Having established two different ways that the league has gotten better over the last two decades, let's zoom in on this graph of NBA quality over the last two decades to see how much play has improved.
Kevin Pelton
Don't tell Scottie Pippen and the rest of his teammates on the 1995-96 Bulls, but this method suggests that the post-expansion league they dominated was nearly 20 percent weaker than the one the Warriors are competing in now. In fact, because of expansion, the NBA in 1995-96 rated only about as strong as it did a decade earlier when the Boston Celtics went 67-15.
Bulls vs. Warriors, adjusted for league
Before dismissing Chicago's accomplishments against a watered-down league, keep this in mind: Even with the more aggressive adjustment for quality of play, the 1995-96 Bulls still rate as better than any NBA team before this season by the method I used to rank the top 50 teams ever last June.
However, the adjustment is big enough to push Chicago behind this season's Golden State team in terms of regular-season performance. Multiplying the Bulls' actual point differential by the estimate of league quality in 1995-96 suggests Chicago would outscore 2015-16 opponents by 10.1 points per games -- similar to last season's 66-16 Warriors (plus-10.1), but now behind this season's Golden State team (plus-10.6).
To truly surpass the 1995-96 Bulls, the Warriors still have to back up their strong regular season by winning a championship. If Golden State can do so, the quality of the league it has dominated means the Warriors deserve to be considered the best team in NBA history.
― k3vin k., Thursday, 14 April 2016 22:20 (eight years ago) link