NBA Players Can’t Shoot Straight after the Lockout

All the excitement generated by Jeremy Lin seems to have distracted fans from what’s really happening this NBA season.  Charles Barkley is paying attention, and he said “As a NBA fan, I want to apologize to the fans.  I cannot believe how bad the NBA is right now.” Offenses are performing poorly this season and there is a simple explanation, the lockout that delayed the start of the season and all but eliminated team practices.

This is the second NBA lockout serious enough to result in limited training camps and a shortened regular season; in 1999 the NBA played a 50-game schedule.  NBA lockouts reduce shooting accuracy and these negative effects may persist for several seasons.  Basketball productivity probably declined because pre-season practices, mid-season practices and rests days were curtailed in order to fit 66 games between Christmas and late April.

The following figure illustrates the average effective shooting percentage in NBA regular seasons from 1980, when the 3 point shot was introduced, to the current season (so fare).  The effective shooting percentage is a weighted average of 2 point and 3 point shooting percentages, where each 3 point shot receives one and a half the weight of a 2 point shot.  The figure indicates that although shooting accuracy varies from year to year, it dropped shortly after both work stoppages, and remained lower for several seasons after the 1999 lockout.

I estimated a simple regression that allows for differences in shooting accuracy among teams and correlation in the fluctuations in a team’s shooting percentage from one year to the next.  The regression model suggests that lockouts cause a 1.5% decline in the effective shooting percentage in the first season after a lockout.  The model also predicts that shooting percentages will remain lower because of the time series correlation in shooting accuracy.

The statistical model can be used to predict how the most recent lockout will reduce NBA scoring over the next few seasons.   Combined scoring by both teams is expected to drop by 5.5 points in 2012 and 3.3 points in 2013 due to the reduction in shooting accuracy.

NBA coaches and teams can adjust strategies to mitigate the impact of the prolonged lockout.  For example teams can attempt more (or fewer) 3 point shots and slow down (or speed up) the pace of play.  If these adjustments are made scoring reductions could be somewhat smaller than the model’s predictions.

Some fans believe that the NBA’s 82-game regular season is too long, so that a silver lining of the 2011 lockout is a shortened 66-game schedule.  Whether or not the regular season is too long, compressing a 66 game season into four months has a negative impact on offensive efficiency.  Practices and rest days are important, even for the world’s best athletes competing at the highest level.  The elimination of rest days and practices appears to be relatively more important for basketball offenses.

Linsanity: Why the NBA Eastern Conference needs Jeremy Lin

Jeremy Lin, New York Knicks point guard and Harvard economics graduate, has become an overnight sensation.  He has averaged almost 27 points and 8 assists per game over the past five Knicks games(all wins), including 38 against Kobe and the Lakers last Friday night.  It may sound strange but the Eastern Conference, home of LeBron James and reigning MVP Derrick Rose, needs Lin, who Magic Johnson compared to Steve Nash and John Stockton.

Magic Johnson and Steve Nash are arguably the NBA’s two best point guards in the past 35 years and they played in the West.  Outstanding point guards raise their team’s offensive efficiency by creating better shot opportunities and increasing shooting percentages.   Magic’s Lakers led the NBA in effective shooting percentage six times in the 1980s and never ranked lower than third in the league.  Nash’s Suns led the NBA in shooting for six straight seasons from 2005 to 2010 until Tony Parker’s Spurs led the league in 2011 (four of the top five teams last year were from the West).

Over the past 32 years the average Western Conference team generated 0.8 more assists per game, made 1/2 of one percent more of their shots, had 1.3 more possessions and scored 2.4 more points per game than their Eastern Conference rivals.  (All of these differences are statistically significant with probability values less than .00001).  The Western Conference has been the home of more efficient offenses, as the result of better point guard play, since the introduction of the three point basket.

The Nets will probably lose Deron Williams, their star point guard, if they do not attract Dwight Howard to Brooklyn.  Another outstanding Eastern Conference point guard, Rajon Rondo, has been the subject of trade rumors since the lockout ended.  The East/West imbalance in point guard play will be exacerbated if Williams or Rondo moves to a team in the West.   But if Jeremy Lin continues on the pace he established in the past five games, the East will begin to narrow an offensive efficiency gap that has lasted for years.