This paper evaluates the per-play impact of special teams on the winning percentage of NFL teams compared to offense and defense. Employing data from the 1999-2022 NFL seasons in the nflfastR database, we developed a new calculation for Expected Points Added (EPA) to accurately assess the contribution of special teams plays, including punts, kickoffs, and field goals, independent of coaching decisions. This methodology allowed us to create our Special Teams Performance Index (STPI), a composite metric that consolidates the performance of all special teams units on a team. We then used STPI in combination with offensive and defensive ratings from ProFootballReference in a regression model to evaluate the importance of special teams on winning percentage. Finally, since there are fewer plays on special teams than on offense or defense in a game, we adjusted the resulting numbers to find the impact on a per-play basis.…Read More
