Yesterday, Pro Football Focus released a review of their advanced quarterback rating system known as the “average depth of target-adjusted completion percentage.” If you’re a metrics nerd (like me), it’s worth taking a look at as it paints a more accurate picture of how quarterbacks perform based on the types of throws they’re making. The formula is as follows:
*aC% = (Completions + Drops) / (Pass Attempts – Spikes – Throwaways – Batted Balls – Balls disrupted by a QB hit)
For clarification, aC% is an adjusted completion percentage. Feel free to click the link yourself for a well-detailed description of the statistic, but essentially it rewards quarterbacks for completions of low-percentage passes (deeper throws), and punishes them for leaning more on high percentage passes (short throws), and adjusts their quarterback rating as needed. Hypothetically, say two quarterbacks achieve a respectable rating of 100.0, but one only completes easy passes to the flats or on screen plays and the other lights up their opponents with downfield tosses, the metric helps add some context to each player’s relative performance based on pass difficulty.
The list ranks each quarterback based on the difference between a quarterback’s expected completion percentage as a result of the difficulty of passes they’ve attempted and how well they performed above that expected rate. Among the top three were Green Bay’s Aaron Rodgers, who performed 6.8% better than expected, followed by San Diego’s Philip Rivers (5.9%) and Chicago’s Josh McCown (5.6%). For what it’s worth, Rivers had just about double the attempts of both Rodgers and McCown, which makes his adjusted percentage that much more impressive.
So where did Rams’ Qbs fit in? The article actually devotes a section to Sam Bradford who, like Rodgers, had his snaps limited due to injury. Bradford’s 75% adjusted completion percentage was seventh-best among all of PFF’s qualifiers, a number that looks impressive before the new metric is added in.
Due to all the short, high-percentage attempts Bradford made prior to his Week 7 injury (Bradford’s average depth of throw was only 7.1 yards, the third-lowest mark among NFL passers), his expected completion percentage was 75.3%. Therefore, he actually performed 0.3% worse than he should have, according to this system. That’s good for 25th among all 48 qualifiers. Additionally, Kellen Clemens average depth of target (9.1 yards) was a full two yards greater than Bradford’s, and his expected completion percentage was a lower 71.9% as a result. However, his actual completion percentage of 69.0% and ensuing -2.9% below that expected performance have him ranked even lower than Bradford at 36th among the 48 qualifiers.
So…uh…think the Rams will draft a quarterback?
What Ram player would you like to see less of in 2014? We say Rodney McLeod.