Calculating Basketball OER and DERBy Dr. James Gels, from the Coach’s Clipboard Basketball Playbook
This page discusses how to calculate your team's offensive efficiency rating (OER) and defensive efficiency rating (DER). I got this information from Coach Chris Mack, former Xavier University Head Coach. Coach Mack says, "Two key numbers for our staff each game are OER and DER. These ratings give us an idea of just how efficient we were on both ends of the court."
Former Xavier Head Coach Chris Mack
The formulas for calculating each are below.
Offensive Efficiency Rating
Where FGA = field goal attempts, FTA = free throw attempts, TO = turnovers
Defensive Efficiency Rating
After calculating these numbers, it is important to understand what is good and what is bad. Below is a quick guide to understanding the results of these calculations.
Below is Xavier's OER/DER spreadsheet for several years:
So assuming you have a statistician or two, you may find calculating this data helpful for your team. For example, by examining the formula, you can tell whether your poor OER is being caused by a low field goal percentage, or poor free-throw shooting, or too many turnovers.