Defense or offense? Which is the better predictor of success for professional football teams?

Data from the 1997 National Football League (NFL) regular season were analyzed to assess whether components that best predicted success tend to be associated more with offense or defense. Analyses indicated that the total number of points conceded by the defense in the regular season explained more variance in success (73.5%) than did the number of points scored by the offense (14.7%). When turnover differential, i.e., the difference between the number of fumbles and interceptions gained by a team's defense and the number of fumbles and interceptions given away by same team's offenses, was included in the model, it explained 43.4% of the variance in success. These and other findings suggest that, outside the 20-yd. zone, the attainments of the defense are more important than are the offensive attainments in predicting the success of NFL teams. Replications of these analyses are recommended using data from previous seasons and including other variables.