Offensive and Defensive Efficiency

Let’s start with Offensive Efficiency.

A team’s offensive efficiency is the amount of points it scores per 100 offensive possessions.

OE = (Points scored * 100) / Possessions

An Example

Let’s stick with the 2019 Championship Game between Virginia and Texas Tech.

Virginia had around 69.93 possessions and scored 85 points. Its offensive efficiency was around 121.6.

OE = (85 * 100) / 69.93 = 121.55

Texas Tech scored 77 points over 70.63 possessions for an OE of around 109.

OE = (77 * 100) / 70.63 = 109.02

Defensive Efficiency

A team’s defensive efficiency is the amount of points it allows per 100 defensive possessions.

DE = (Points allowed * 100) / Possessions

An Example

Following our example above, Virgina’s defensive efficiency is around 109. Virginia allowed 77 points over 70.63 possessions.

DE = (77 * 100) / 70.63 = 109.02

Texas Tech’s defensive efficiency is around 121.6. The Red Raiders allowed 85 points over 69.93 possessions.

DE = (85 * 100) / 69.93 = 121.55

Notice this is the inverse. An opponent’s offensive efficiency equals a team’s defensive efficiency. A team’s offensive efficiency equals their opponent’s defensive efficiency.

Why are these numbers so high?

Remember this is the number of points scored or allowed per 100 possessions. Offensive efficiency isn’t an indication of how many points a team scores. Defensive efficiency doesn’t suggest how many points a team allows.

The final score of this game was Virginia 85, Texas Tech 77. Not 121-109.

In our example above, the game featured about 70 possessions.

The Offensive Efficiency numbers are high because the statistic is over 100 possessions. Not 72 or 70.

Don’t confuse points-per-game with offensive or defensive efficiency.

Why was a team efficient on offense or defense?

A team’s efficiency can be broken into four factors. Remember those factors?

Let’s continue with this same game as an example.

Virginia turned in an offensive efficiency of around 121.

eFG% = 55.1%
OR% = 32.4%
TO% = 15.8%
FTRate = 39.0

Virginia made a solid percentage of its shots, avoided turnovers around 85% of the time, and frequently got to the foul line.

Texas Tech posted an offensive efficiency of 109.

eFG% = 50.8%
OR% = 24.3%
TO% = 11.5%
FTRate = 23.8

While Texas Tech avoided turnovers on almost 89% of its possessions, the Red Raiders rebounded fewer missed shots and got to the foul line less than Virginia. Texas Tech also made a lower percentage of its shots.

This a good reason why Virginia won the game by 8 points. The Cavaliers were more efficient on both ends.