The Evolution of the NBA

I watched a lot of NBATV this summer.  I watched Jerry West and Elgin Baylor trying to carry their team against the Celtics.  I watched Chamberlain and Russell play each other.  I watched the championship Knicks squads.  I watched Moses and Julius.  I watched the 80s Lakers and Celtics.  And thanks to Jordan, Stockton, and Robinson entering the Hall of Fame, I watched a ton of their games.  While watching all of those games, I was reminded that the period covering the late 80s and early 90s was by far the best period in NBA history in terms of the quality of play.  I'm going to talk about why, but also thought I would share some graphs showing the evolution of the NBA.  Here's a graph of league average offensive efficiency (pts/100 possessions) and league average pace (possessions/48 min) from the first season after the NBA/ABA merger through last season.

As you can see pace dropped like a rock beginning with the merger and accelerating when the league moved the 3-point line closer in 94/95 before finally bottoming out during the lockout shortened season of 98/99.  Offensive efficiency was rising even before the 3-point shot was introduced in the 79/80 season and leveled off at around 108 pts/100poss.  The league finally reached that level again just last season.  To get an idea of why league efficiency and pace changed over the last 30 seasons since the introduction of the 3-point line here's a graph of the league averages of the four factors, and I included the league average 3PA/FGA because the 3-point shot has had the greatest impact on changing the game over the last 30 years.

As you can see them most notable change is the increase in 3PA/FGA over the last 30 seasons, growing from just over 2% of shots taken in the early 80s to just over 22% of shots taken last season and accompanying growth in 3-point accuracy.  It would probably be a smooth curve if not for the 3 seasons of the shortened 3-point line. This curve makes sense.  In the early years of the 3-point line players weren't equipped for shooting the 3.  You had a league full of veterans that had never played with it in HS or college.  Even the scorers at guard had skill sets primarily built around getting close to the basket for shots because that was how you won.  The ABA did have the 3-point line, but there weren't a lot of 3s taken, only 4% of FGA in the last season of the ABA for example, because the players didn't grow up with the 3-point line.  In the 1st season of the line 3.1% of shots were 3s.  Apparently a bunch of guys realized they couldn't make it It wasn't until 84/85 that at least 3% of FGA were 3-pointers again.  Over the 80s some players adapted.  Even someone like Magic was knocking down 3s by the end of the 80s.

But, colleges also played a big role in the evolution of the 3 in the NBA.  Beginning with the Southern conference in 1980, individual conferences began adding various 3-point lines.  Now rookies began entering the league with experience shooting 3s in college and that only grew as the standard NCAA 3-point line was adopted in 1986. And now for the last twenty years every player has grown up with the 3-point line as a part of youth basketball, and it's become a constantly increasing feature of basketball at the lower levels.

The rise in the frequency of the 3-point attempt has resulted in the steady decline of pace with the league bottoming out at basically the limit of what the 24 second shot clock would allow.  There was a huge incentive to score on the fast break before the 3-point shot, but the possibility of launching a 3 at the end of shot clock has largely erased that incentive.  While the pace of the game has rebounded some, it's hard to envision the league average traveling north when of 95 again.  The rise of the 3-point shot also coincided with a steady decline in offensive rebounds. There's more offensive rebounds in fastbreak situations and on shots close to the basket, the 3-pointer both devalued the marginal fastbreak opportunity and the marginal shot close to the basket.

As I said, I believe the late 80s and early 90s was by the best period of NBA basketball.  By then the 3-point shot had created the floor spacing that didn't exist in prior years.  It was always 6 or 7 players within a 15 foot radius of the hoop.  The Lakers won two championships and went to three finals in the 1st four seasons of the 3-point era, despite never having more than 100 3PA in the regular season.  The 76ers won the 83 championship with only Andrew Toney attempting more than 8 3s in the regular season, and they shot 1 for 10 on 3PA in the playoffs.  Then in 83/84 the Lakers suddenly took 226 3PA as Michael Cooper began taking over a 100 3PA.  By 86/87 5% of FGA were 3PA and most teams, especially the good teams, had at least a couple of solid 3-point shooters on the roster spacing the floor.  But, fewer than 10% of FGA were 3PA as late as 91-92.  Denver led the league with a 1005 3PA that season, only the Thunder failed to break 1000 3PA that season.  The Bulls had 454 3PA as a team in 91-92 and Ben Gordon had 422 3PA just last season.

The late 80s and early 90s was this period where the league reached it's historical peak of offensive efficiency.  Yes, the NBA reached that same peak efficiency last season.  And I am pleased by the recent trends in the NBA,  but the present offensive efficiency reached on the back of 3-pointers and and unchecked dribble penetration by guards doesn't match the late 80s and early 90s qualitatively in my book.   In the late 80s players had adapted to the 3-point shot and the resulting increase in floor spacing had boosted offenses, but not taken over offenses.  Pace was declining during this period, but was still above 96 poss/g through 92/93.  Turnovers were down and offensive rebounding still hadn't declined very much.  Players leaving college before their junior year of college hadn't really hit the NBA yet.  And most of all the NBA had this blend of players with the post up and mid-range skills necessary to play in an era without the 3-point shot and players with the ability to make the 3 and space the floor that resulted in the highest quality of play the league has ever seen.  And then there was also the intersection of so many of the greatest players in NBA history.  It just was the best period of basketball in my opinion, and unfortunately it can never be that way again.

If you want to look at the numbers behind the graphs here's the spreadsheet.