Considering FiveThirtyEight's 10 types of NFL quarterbacks

Nothing inspires spirited debate quite like quarterback rankings. Dan Marino is a bum because he doesn’t have a ring. Eli-face is better than Peyton-forehead because at least Eli-face can beat Tom Brady. Never mind the fact that Brady doesn’t play defense.

Perhaps the biggest crime people make, though, is treating quarterbacks as though they can only exist in one of two binary states: Elite and Bust. There is no other option. Either you are Aaron Rodgers or you are Brady Quinn.

Enter Noah Davis and Michael Lopez. Instead of feeding the binary beast, they use ESPN’s total QBR to devise 10 types of quarterbacks. The too-long-didn’t-read summary of the article? Better quarterbacks will have more games in the upper QBR scores. Using density curves, you can identify 10 distinct categories of quarterback.

Think what you will of QBR, but it’s simply an explanatory statistic that includes more varied inputs than the traditional QB rating. QBR takes QB’s running prowess into account, and two NFC West quarterbacks, Colin Kaepernick and Russell Wilson, are perfect examples of how a QB’s legs can negatively affect defenses.

That’s not to say QBR is perfect. There are some serious issues, many detailed by Doug Farrar. The idea of clutch-ness and blame sharing sounds good in theory, but these kind of subjective "measurements" only muddy the rating waters. QBR has it’s issues, but simply because Davis and Lopez use the QBR number doesn’t mean you can discount their findings.

Of interest to 49ers fans is that the density curve analysis places Kaepernick in the "Second tier" category, a cohort consisting of Matt Schaub, Andrew Luck, Tony Romo and Teddy Bridgewater.

Whether you agree with the density curve analysis or not, it’s clear that quarterbacks should be considered more than "Elite" or "Bust." And somewhere, Joe Flacco is smiling.

What do you think? Do the categories described make sense based on what we see on Sundays? Any of the quarterback groupings surprise you?