QBR: Bradford, Smith and the division

Unsettled quarterback situations elsewhere in the NFC West made the St. Louis Rams a logical early favorite to win the division in 2011.

The Rams had the very promising Sam Bradford, after all, while the rest of the West was going through quarterback identity crises.

Extensive field testing has shown that peppering a well-informed San Francisco 49ers fan with such logic can produce entertaining (for the rest of us) results. The embattled 49ers fan, no matter how repulsed by the thought of another season with Alex Smith behind center, will sometimes retrieve from his statistical weapons cache this improbable bombshell: Smith was the highest-rated passer in the division last season.

And it's true. Smith finished the 2010 season with a borderline-respectable 82.1 rating, even though his team struggled to a 6-10 record. Bradford's rating was 76.5, with Matt Hasselbeck at 73.2. But what if we viewed these players' contributions through the new "Total Quarterback Rating" (QBR) tool set to launch for the upcoming season?

I do not yet have all the details on how the formula works -- ESPN will discuss those in depth during a "SportsCenter" special Friday -- but I did secure QBR numbers for a few quarterbacks relevant to this discussion. QBR evaluates quarterbacks on a 100-point scale, reflecting how a quarterback's performance on each play affects game outcomes.

In preparing this item, I asked ESPN Stats & Information for examples of quarterbacks with similar passer ratings and disparate QBR numbers. We might then better illustrate how passer rating differs from QBR. Smith and Tennessee's Kerry Collins provided one such example. Their passer ratings were nearly identical, but Collins scored much higher in QBR.

Collins' 56.0 rating in the new metric was six points higher than the average established by all quarterbacks across roughly 60,000 plays since 2008. Smith was well below average in QBR at 40.0, affirming what I suspect most of us intuitively know about these quarterbacks. In this example, the QBR seems quite helpful.

Smith took sacks at a higher rate than Collins. They threw interceptions at a nearly identical rate, but the QBR formula considered Smith's interceptions far more costly to his team, according to Alok Pattani, one of two analytics specialists assigned to the QBR project. QBR also viewed Bradford and Hasselbeck more favorably than it viewed Smith.

In another example, QBR rated Peyton Manning much higher than it rated Matt Schaub last season, even though Schaub finished with a slightly higher passer rating (92.0 to 91.9). Schaub took twice as many sacks while fumbling three times as frequent.

Manning's QBR was 69.5, right around where we might expect a Pro Bowl-caliber quarterback to rate. Schaub's QBR was 57.8, above average but not as high as his passer rating ranked in relation to other quarterbacks.

On Bradford, I'm interested in knowing more about how his depleted receiving corps affects his standing in QBR. While he was better than Smith in QBR, I anticipated a greater margin. Bradford ran out of weapons at receiver and leaned heavily on short passes with little potential. Likewise, the challenges Seattle faced on its offensive line put Hasselbeck at a severe disadvantage, I thought. These are all things to explore once QBR makes its formal debut Friday.

2010 QBR Comparison