Last updated: Week 17 2019
The NFL Cowardice Index is a way to rank cowardice of NFL teams and plays. Cowardice is a measure of how much teams cost themselves by (usually) punting.
On any 4th down, a team has 3 options: go for it, kick a field goal, or punt. For each of these possibilities, we calculate win probability for the offense. We also factor in how likely a team is to convert a 4th down given the yardage to go, or make a field goal given the distance.
Cowardice only applies to punts and field goals on 4th down. We assume going for it is never cowardly.* The cowardice of a play is the difference in win probability between the best of the 3 options and what a team actually called.
For making the bravest call, a play gets a cowardice rating of 0. If kicking a field goal would have increased your win probability by 5.1%, and you chose to punt, which decreased your win probability by 1.7%, that play would have a cowardice rating of 6.8%.
Win probability is calculated via Andrew Rook's NFLWin. It takes field position, down and distance, score, and time remaining into account. Field goal/4th down conversion rates are calculated by linear regression of historical conversion rate vs. distance. Punts are assumed to go 100% of target distance punted. The average open-field punt is taken to be 47 yards, the average gross punting distance from the 2018 regular season.
The dataset contains every play from 2009 through the date listed at the top of the page. It includes the regular season and playoffs. Questions? Email me at firstname.lastname@example.org.
* This also helps avoid counfounding last-play situations, where you might safely kick a field goal to tie, or take a shot at a lower-percentage touchdown and the win. Going for the win in that situation surely isn't cowardly.