NBA: Shooting Efficiency Across Era's

Since the late 1940's there have been many changes in North America's major pro basketball league.  The shot clock, the merger of the NBA & ABA, introduction of the 3-point line, shortening the distance of the arc, moving the line back out, coaching philosophy's and rule changes related to zone defenses & hand checking.

If you ignore context for NBA seasons, especially those before the 3-point line, you miss many elite scorers from the first three decades of The Association.

In order to normalize performances from different eras we need a constant baseline for every NBA season.  Comparing scoring to the league average each year is one tool we can use to get a clear idea of the offensive value every player has brought to his team.

The chart above displays shooting efficiency as 'Points per 100 Shot Attempts'.  This data-point going back each season to 1947 is used throughout NBA Metrics and forms the foundation of stats like True Shooting+ and Points Above Average.