Thursday, May 9, 2013
Expanded look at QB wins above average
By Mike Sando
Les from Philadelphia read our recent piece on quarterback victories over average and wondered if we could apply the same approach to other teams.
"Can you do the same analysis for other QB-challenged teams such as Philadelphia, Minnesota, etc.?" Les asked.
We can take a shot at it, Les. First, a quick primer on the methodology.
Total QBR measures quarterbacks' contributions to winning on a 100-point scale, with 50 as average. The scores correlate with a team's likelihood of winning a game. In other words, a team scoring 50 in Total QBR would, on balance, win about half its games. The chances for winning would be 75 percent for teams with QBR scores around 75, and so on.
With this established, we can calculate the wins over average a quarterback provides over the course of a 16-game season. We simply average his single-game QBR scores, subtract 50 from that number, convert the result into a percentage and multiply by 16.
A quarterback with a Total QBR score of 75.0 would provide four victories over average, for example (75 minus 50 equals 25, and 25 percent of 16 is four).
The first chart ranks 2012 quarterbacks with at least four regular-season starts by wins above average, based solely on their single-game QBR scores last season. The San Francisco 49ers' Colin Kaepernick and the Seattle Seahawks' Russell Wilson ranked among the NFL's best.
The second chart shows the quarterbacks with the worst figures for wins above average. These quarterbacks' performances reduced their teams' chances for winning by 1.5 to 5.3 games per 16-game season.
The Arizona Cardinals' Ryan Lindley (minus-5.3) and John Skelton (minus-5.0) top that list. Kevin Kolb was better, but he was still eighth-worst in the league at minus-1.9. Note that the figures for these quarterbacks project their impact as if each played a full season. Skelton and Lindley combined to start 10 games.
Les asked about Minnesota and Philadelphia.
The Vikings' Christian Ponder was 19th at plus-0.2 wins above average. His single-game QBR scores averaged out to 51.5 in 16 starts. The Eagles' Michael Vick (minus-1.5) and Nick Foles (minus-0.8) ranked lower.
We'll revisit this information as the offseason continues.
The chart below takes a longer-term approach. It shows wins above average over a 16-game season based on single-game QBR scores since 2008. I added a column for expected wins if these quarterbacks played for teams that were average in other ways. By this method, expected wins are simply wins above average plus eight. We might think of Peyton Manning as a 12- or 13-win quarterback based on how he played last season. Note that some quarterbacks making surprise appearances on the list played fewer games.
Peyton Manning appears twice, once for his work with Denver last season and also for his contributions with Indianapolis previously. The Denver-era Jay Cutler also appears. The Chicago-era Cutler has been far less impressive, checking in at plus-0.3 wins over average. That version of Cutler doesn't appear in the chart.