Up on Grantland right now is an article which basically sums up all the reasons why most stat-heads think the niners will regress in 2012. (http://www.grantland.com/story/_/id/8237657/san-francisco-repeat-last-season-greatness) For those that buy into this sort of predictive analysis, here's a response to consider.
The author of the Grantland piece uses a few statistics to make his prediction that the niners will regress and finish around 8-8 this year. Here are some of them, summarized:
Record: 13-3, up from a 6-10 record last year (+7 wins)
Turnover differential: +28 (#1 in NFL)
6-2 record in close games (games decided by 7 or less)
Pythagorean record: 12.3-3.7 (Pythagorean record: predicting a team record based on ratio of points scored vs. points allowed, so we outperformed our "expected record" by a game)
All three of those things fluctuate wildly from season to season, says the author. In other words, being good at them for one year probably doesn't portend continued success going forward.
But consider another example, "Team A".
Record: 13-3, up from 6-10 the prior year (+7 wins)
Turnover differential: +23 (#1 in NFL)
7-2 record in close games
Pythagorean record: 11.2-4.8 (+2 wins from expected record)
Team A is due for an even bigger regression, right? No hope of continued success. Except...Team A is the 1981 49ers, whose season marked the start of one of the great runs of dominance ever.
Food for thought when reading about the many niners doubters this offseason.