Density curves are a useful way to compare per-game performance. The data for this analyis uses each NFL QB's per-game Total QBR for all games dating to 2006, which is as far back as the data allows.

The tab `QB curves' graphs the density curves for any selected player.

The tab `Home/away splits' shows curves split by home and away games.

The tab `Similarity Curves' shows the three players with the closest density curves to the selected player. Quarterback similarity is judged using a function of the Kolmogorov-Smirnov test of distribution equivalence.