Whenever I see NBA team stats in the newspaper or online they are almost always sorted by PPG, both offensively and defensively. Unfortunately, using PPG to rank teams offensively and defensively is very misleading. A team that runs and doesn't get back on defense will have a higher PPG, yet that team may not be a very good offensive team. A better measure of a team's offense is the number of points scored per possession. The key word in that last sentence is "possession". It is unbelievable that the possession is not a staple of the NBA stat page. The possession is the building block in the comparison of NBA teams and can be used to determine the superior team in just about any category.
First, let's start with some logic. Team A averages 100 possessions per game (ps/g) and Team B averages 110 ps/g. If Team A and Team B both average the same number of points per possession, then Team B will have the greater PPG and appear to be the superior offensive team, but in reality they both score at the same rate. If these teams played each other then one could expect a very even game, since the number of possessions in that game would have to be equal for both teams. This is why using PPG to determine the outcome of a game is very foolish.
But what is a possession and how is it calculated? A possession is defined by the following formula:
P
Possessions = FGA + TO - Oreb + (FTA*.44)
The only tricky part to this equation is the (FTA*.44) segment. The constant of .44 was determined by John Hollinger by as the best fit to current data.** I've also seen .4 as the constant, but for the purposes of this site we will use .44.
Now that we have our building block for comparison, let's take a look at how we can use it. If we want to see which teams are better offensively than others then we would take their total points scored and divide it by the total number of possessions and get pts/ps. But most people are so conditioned to seeing per game averages that it is easier to look at points per 100 possessions because an NBA game has roughly 100 possessions. This final value is called offensive efficiency. The offensive and defensive efficiencies of NBA teams can be viewed at basketballreference.com.
Knowing the offensive and defensive efficiencies are very important when handicapping an NBA game. This information, along with ps/g and pts/ps, will be listed on coverwire.com so that you can place a more educated bet. I really don't understand at all how other betting sites cannot post this vital information because it plays a very important role in determining the outcome of the game.
Questions? Comments? Send me an email at computerguy@coverwire.com