QB Rating

I am compelled to write this, as I finally have a forum where at least (at most?) one other person will see what I have to say!  I am writing this to *GASP!!!* defend the traditional quarterback rating system.  The current quarterback rating system is not the embodiment of voodoo magic that advanced statisticians and ESPN would lead you to believe (good old double-talking ESPN... promotes their Total QBR system, but lists the traditional number on the players stats pages!).  It is really a very simple formula, which I'm not going to look up right now.  Here is what matters.  TD passes matter.  Interceptions matter.  Yards per attempt matter.  Completion percentage also matters.  While TD passes can be inflated (see the 2011 season when the Packers always threw in the endzone), interceptions do not typically suffer from this problem.  If a QB throws enough times to be considered the team's primary QB, the interception number will tell a very important story.  Finally, yards per attempt is perhaps the most important.  A high yards per attempt, over the course of a season, describes the ability of the QB to throw the ball down the field accurately.  On a game-by-game basis, this statistic can be inflated by YAC, but over the course of the season, this number tells much more about QB play.

The reason I care so much about this is because everybody complains about this statistic for the wrong reason.  It does not take into account running plays.  While the ability to avoid pressure is important, the ability of a QB to run is secondary to the ability to throw the football.  The other complaint, which is really bizarre, is that the number is difficult to understand because a perfect rating is 158.3, not 100.  The comment I love most is "how is 158.3% perfect, when you can't get above 100%?"  The simple explanation:  QB rating is not a percentage!  What would it be a percentage of, if it were?  It is an arbitrary number by which QBs can be compared to each other, not a percentage of anything.

If I could change anything about this statistic, I would find a way to era-adjust it, as passing has become easier.  For example, hall of fame QBs like John Elway had ratings in the 80's.  These days, the great ones have ratings in the low 100's.  However, I would not argue to use this statistic for generational comparison, as the numbers for greatness have changed so drastically.  However, I would argue that on a year by year basis, or as a comparison between the careers of peers of the same era, this statistic is very valuable.