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Monday, September 10, 2012
QBR ranks: Alex Smith stands tall on road

By Mike Sando

San Francisco 49ers quarterback Alex Smith isn't one to seek validation through statistics.

He has openly questioned some of the most basic ones.

"This is the honest truth: I could absolutely care less on yards per game," Smith said during the offseason. "I think that's a totally overblown stat. Because if you're losing games in the second half, guess what? You're like the Carolina Panthers and you're going no-huddle the entire second half and, yeah, Cam Newton threw for a lot of 300-yard games, that's great. You're not winning, though."

The comments stirred controversy and risked discounting some of the truly positive contributions Newton made to his team last season. But what Smith said about quarterback stats was generally accurate. Cheap yards don't matter so much.

ESPN, seeking a superior metric for quarterbacks, introduced Total QBR last season. On the NFC West blog, we debated its merits, considered potential improvements and sought to learn from results that surprised on the surface. We'll do the same thing each week during the 2012 season, beginning with this entry. The goal will be to more fully understand how quarterbacks affected game outcomes.

Dean Oliver, hired from the Denver Nuggets as ESPN's director of production analytics, helped to develop and refine QBR. Because QBR measures how quarterbacks affect win probability on a per-play basis, teams winning the QBR battle will usually win their games unless something unusual beyond the quarterback's control influences the outcome.

Since 2008, teams with the higher QBR score won 86 percent of their games (the figure was 79 percent for NFL passer rating, 78 percent for turnover margin and 70 percent for total yardage).

Smith's performance during the 49ers' 30-22 victory at Green Bay produced his second-highest QBR total on the road since 2008, which is as far back as the metric goes. His 83.5 score out of 100 far outpaced the 55.1 for Packers counterpart Aaron Rodgers. Fifty is considered an average score and will generally give a quarterback about a 50-50 shot at winning. A quarterback producing a total like Smith's from Sunday can expect to win more than 80 percent of the time.

Quick thoughts on how NFC West passers graded out in Week 1 in relation to Total QBR, with NFL passer ratings in parenthesis as a reference point:
The chart below shows how quarterbacks from games involving NFC West teams fared in Total QBR for Week 1, provided they played enough to qualify for inclusion.

The column showing point above average reveals the "number of points contributed by a quarterback over the season, accounting for QBR and how much he plays, above the level of an average quarterback."