publishes my favorite football statistic: Defense-adjusted Value Over Average. DVOA for short, their statistic compares player and team performance to the league average in similar situations.

DVOA can only be precisely calculated using play-by-play data, available since 1989, but Andreas Shepard recently estimated DVOA going back to 1950 and wrote about it on Football Outsiders. Chase Stuart worked with him to write another piece on

I used the data from those articles to create this interactive visualization of DVOA history.

In addition to the insights from Andreas' and Chase's articles, here are a few observations from playing around with these charts.

Feel free to lob me an email at with any comments, questions, or ideas. All the source code for this project is on GitHub.