Defense Wins Championships

One of the oldest cliches in professional sports is that Offense puts people in the seats, but Defense wins championships.  With the NBA playoffs in full swing now, its as good a time as ever to examine how true it is for the league.  To see just what effect both play, we’ll start by looking at which teams make the playoffs versus those that don’t. 

From 2004-2012, the league average efficiency on both sides of the court averaged right around 107 points per 100 possessions.  The average that a team needed to hit offensively to be amongst contenders was 108.2, while teams that failed to qualify averaged in at 104.8.  These numbers are pretty close to their defensive counterparts (109 for non playoff teams, 104.6 for playoff qualifiers).  The below chart gives a pretty good overview of how league scoring has trended, with a rise until the 2008 season followed by a pretty sharp drop off

We do see the old cliché holding, with team’s that made the playoffs sporting a better than league average defensive rating at a statistically significant level.  We also though see these same teams holding a significant offensive edge over their less competitive peers.  To advance in the playoffs though, does it take being a grittier defensive team? 

The data says not particularly moreso than being a good offense.  Teams that advanced through the first round typically shared again the fact that they were superior to their opponents in both phases of the game.  During the studied period, the typical teams meeting in the championship also did not display a real difference between their offensive or defensive capabilities.  Both held well above league average offenses and defenses though.

So, it would seem that the mantra has some weight, as teams that were better than league average were more likely to make the playoffs.  However, they were not so much more likely than the teams that played superior offense to do so.