We all know the number of publications and analysts, led by FootballOutsiders, that are saying the 2011 49ers were a bit of a fluke and should return back to an average team in 2012.
Contrary to that statement, I want to draw attention to "Pythagorean Wins", a metric used by most advanced sports statistics (and I think FO uses it too). What it does is look at points scored vs points allowed and converts it into an 'expected' winning percentage.
I'll let Grantland explain it:
How It Works: Created by Bill James for baseball and modified for football in the early '90s by current Houston Rockets general manager Daryl Morey, the Pythagorean theorem (or "Pythagorean expectation") is a formula that translates a team's points scored and allowed into an "expected" winning percentage. That formula isn't exactly for the faint of heart:
Points For^2.37 / (Points For^2.37 + Points Against^2.37)
As an example, let's take the 2011 Chiefs, who went 7-9 while scoring 212 points and allowing 338. Our formula is 2122.37 / (2122.37 + 3382.37) = 0.248. That's the Chiefs' expected winning percentage from their point differential, and if we multiply it by 16 games, we get a total of just 4.0 wins. The Pythagorean theorem suggests that the Chiefs outperformed their true level of performance by three full wins.
Now, if you compare actual wins to expected wins, the 49ers were #1 in the NFL (regular season) in Pythagorean wins, edging out New Orleans (barely) and Green Bay. If you adjust that number for their Adjusted Strength of Schedule (aSOS) [which is opponents winning % excluding their own games], the 49ers are still #1, basically tied w/ the Packers. Comparing actual wins to Pythagorean wins, The 49ers aren't much different. The Chiefs and Packers each had 3 more wins than they should have, while the Vikes and Dolphins each should have had 2.5 more wins.
I've posted the data below in a spreadsheet. We clearly won as many games as expected...the 6-2 record in close games is somewhat meaningless. In contrast, the Packers should have went 12-4. I suspect this is somewhat due to 'Superstar Quarterback Fetishism" that so many NFL commentators are guilty of nowadays.
Going forward, you would adjust last year's numbers for 2012 strength of schedule and any improvements or declines a team experiences. For the 49ers, we have all 11 starters coming back on Defense -- a young defense -- and we dramatically upgraded what was arguably our weakest spot: the WR Corps. We also have the same coaching staff and system, with Smith in his second year in the same system for the first time ever.
As a result, I argue that the only argument you can make against the 49ers is that they're either (1) due for a ton of catastrophic injuries or (2) they'll under-perform their Pythagorean wins. And, if they under-performed their Pythagorean wins, the worst we would perform is 9-7 or 10-6.
summary: if the 49ers stay healthy, expect 12 wins, +/- 2 games.