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
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
A team’s defensive efficiency is the amount of points it allows per 100 defensive possessions.
DE = (Points allowed * 100) / Possessions
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.
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.
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.