About the data
Where it comes from
All data comes from nflverse, a free, public project that publishes official NFL play-by-play data with added measures such as expected points added (EPA). I downloaded the ten seasons from 2016 through 2025, one file per season (484,254 rows and 372 columns in total). The scripts that download, clean and analyze the data are in the GitHub repository, so every number on this page can be reproduced.
What one row is
One row is one play: one team's offense on one snap in one game, with the season, week, teams, down, distance, field position,
score, play type and result. The cleaned file (data/plays.csv) has 419,148 rows and 28 columns. A second file
(data/games.csv) has one row per game (2,761 games) with the final score.
Rows I dropped and why
- No-plays: a penalty wiped out the play, so no result counted.
- Non-plays: timeouts, end-of-quarter markers and the two-minute warning.
- Kneel-downs and spikes: plays that only run or stop the clock, not real attempts to gain yards.
- Broken rows: a handful with no offense or no EPA value.
That removes 65,106 rows. The report uses regular-season games only (400,398 plays); playoff games are kept in the data file and can be added on the dashboard.
How each number is calculated
| 4th-down go rate | Go-for-it attempts (runs and passes) ÷ all 4th-down plays that were a run, pass, punt or field goal try. |
|---|---|
| 4th-down conversion | A go-for-it attempt that gained at least the yards needed or scored a touchdown ÷ all go-for-it attempts. |
| "Choice" 4th down | 4th and 2 or less, in quarters 1–3, with the score within 7 points. |
| EPA per play | Average expected points added (from nflverse's model): how much a play changed the number of points the offense can expect to score. |
| Success rate | Plays with EPA greater than zero ÷ all plays in the group. |
| Pass rate | Pass plays ÷ (pass plays + run plays). Sacks count as passes; quarterback scrambles count as runs (nflverse's labels). |
| Team win % | (Wins + ½ × ties) ÷ games played, regular season. |
| Aggressiveness groups | Team-seasons sorted by go rate and split into four equal groups (quartiles); the win % shown is each group's average. |
| Expected points per try | Two-point: success rate × 2. Extra point: success rate × 1. |
| Field goal rate | Made field goals ÷ attempts (blocked kicks count as misses), grouped by kick distance. |
| Kickoff return rate | Kickoffs where a player fielded the ball to return it ÷ all kickoffs. Touchback rate is touchbacks ÷ all kickoffs. |
| Home win % | Games won by the home team ÷ games that did not end in a tie. |