Defensive Efficiency Ratio (DER)

The Defensive Efficiency Ratio (DER) measures how well a football team prevents opponents from gaining yards and scoring. It calculates the average yards allowed and points conceded per game relative to how often the team is on the field and its offensive performance. A lower DER indicates a more effective defense, meaning the team gives up fewer yards and points while facing fewer offensive drives. Essentially, DER provides a comprehensive view of defensive performance by accounting for both yardage and scoring, helping to assess a team's defensive strength relative to their opponents' offensive productivity.