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[You can find lots of websites previewing each team as we head towards the 2012 season. You won't find that at FootballPerspective.com, but instead, I'll share some random thoughts on each franchise based on well, whatever springs to mind. We'll kick things off with look at the San Francisco 49ers.]

The 49ers are an interesting team to me because they seem like the ideal candidate to regress. Generally, teams that make huge jumps in one season are better candidates to fall back to the pack than elite teams with a history of success. Additionally, defensive teams are generally less likely to retain their success than offensive teams. But since I don’t expect you to just believe me…

I looked at all teams since the AFL-NFL merger in 1970 that won at least 75% of their games (San Francisco went 13-3 last year) and then separated them based on their records in the prior season (the 2010 49ers went 6-10). There were 155 of them, and how they performed in the year before (Year N-1) their elite season was relevant in determining their record in the year (Year N+1) after that big season. The table below breaks down the teams based on their winning percentages in Year N-1 (for our purposes, that’s 2010 for the 49ers) and then shows how well they performed in Year N+1 (for our purposes, the 2012 49ers):

Year N-1
# of Tms
N-1 Win%
N Win %
N+1 Win %
Over 80%2486.3%79.7%67.2%
70-80%3274.2%81.5%70.2%
60-70%3965.1%80.6%62.6%
50-60%3553.8%79.6%63.2%
<50%2536.8%79%53.6%
Total15563.1%80.2%63.5%

Just so we’re all on the same page, the top row of that table informs us that of the 155 teams to win at least 75% of their games, 24 of them won over 80% of their games in Year N-1. On average, those teams won 86.3% of their games in Year N-1, 79.7% of their games in Year N, and then 67.2% in Year N+1. The 49ers would represent a team in the bottom row. There have been 25 teams like the 2011 49ers who won at least 75% of their games after having a losing record the prior year (on average, those teams won just 37% of their games – just like the 2010 49ers); in the following year (e.g., the 2012 49ers) those teams won just 53.6% of their games.

So while it’s easy to see many, many differences between the 49ers of 2011 and of 2010, “breakout” teams have been less likely to remain elite than teams with a longer track record of success. I ran a regression on this set of data, and every win in Year N-1 correlates to an extra quarter-win in Year N+1. A team that goes 13-3 in consecutive years is projected to win 11 games in Year N+1; a team that goes 9-7 and then 13-3 is projected to go 10-6, while the 49ers would be expected to win just over 9 games based on their 6-10 record in 2010.

The 49ers also had a severe offense/defense split. San Francisco ranked in the top 4 in both points and yards allowed, while ranking 11th in points scored (thanks in part to great special teams) and 26th in yards (thanks in part to Alex Smith). I calculated an average (based on points and yards) offensive and defensive rank for each of the 155 teams and then ran a regression on that data. As it turns out, a team’s offensive rank is nearly twice as useful in predicting wins in Year N+1 than a team’s defensive rank. A team that wins 80% of their games in Year N and ranks 3rd in offense and 18th in defense is projected to win 10 games, while a team like San Francisco that ranked 3rd on defense and around 18th in offense would be projected to win 9 games. Ranking the 155 teams from most defensive heavy to least defensive heavy revealed similar results. The 20% most defensive heavy teams won an average of 9.3 games the following year, compared to 10.3 wins for the most offensive heavy teams. 1 Simply put, offensive teams are simply more likely to retain their value.

And, of course, the results become magnified when you combine the two factors. Running a regression on these 155 teams looking at their Year N-1 and Year N records, along with the average of their offensive yards and points ranks and the average of their defensive yards and points ranks, shows how vulnerable to a slide the 49ers truly are. A team that had won 13 games in consecutive years and ranked 3rd in offense and 18th in defense in Year N would be projected to win exactly 11 games — picture a team similar to the Patriots. A team that had gone 6-10 and then 13-3 on the strength of the 3rd best defense and the 18th best offense would be projected for only 8.5 wins. So where the 49ers came from and how they won matter, arguably to the tune of 2.5 games. Not all 13-3 teams are created equal, and San Francisco looks to be one of the weaker ones based on these factors.

However, there’s another thing to note about the 49ers. Most 13-3 teams are lucky; the average 13-3 team is much more likely to be an 11-5 team that gets a few breaks than a 15-1 team that was unlucky, simply because there aren’t many teams whose true strength is that of a 15-1 (or 14-2) team. But San Francisco, at least by one metric, wasn’t particularly lucky.

The 49ers had an expected win-loss record of 12.3-3.7 last year, based on having scored 380 points and allowing only 229. The 49ers lost to Dallas in a game where the Cowboys needed a 48-yard field goal on the final play of regulation just to force overtime. Against the Cardinals, San Francisco led most of the game before ultimately losing by two points. San Francisco’s other loss was a 16-6 loss in Baltimore on Thanksgiving night, and a borderline penalty call on what would have been a Ted Ginn touchdown arguably tipped the scales in the Ravens’ favor.2 Then in the playoffs, the 49ers defeated the Saints and nearly toppled the Super Bowl champion Giants. There wasn’t a game last season when San Francisco looked outmatched. The average expected 16-game win total of the 155 teams in the above study was 11.8, so at least on some level, the 49ers were even above average based on their record.

Alex, stay right here. Don't move, I'll be right back, I just have to do one quick... Hey Peyton!

Of course, the 49ers were lucky in several ways, or rather, were extremely fortunate in ways that are unlikely to repeat themselves. One, San Francisco had the best special teams in football last season (according to PFR’s expected points statistics, San Francisco gained roughly 67 points over their opponents due to special teams play, highest in the league). Two, San Francisco pulled off the extremely rare feat of leading the league in both giveaways (10) and takeaways (38); that differential tied for the second largest advantage since 1970. Additionally, San Francisco had a relatively easy schedule last season, and their schedule this year doesn’t appear to have many “gimmes.”

As I wrote last season, I love what Jim Harbaugh has done and think the 49ers are well-positioned to be a contender for foreseeable future. Fortunately, Harbaugh hasn’t rested on last year’s laurels, bolstering the offense with the additions of Randy Moss, Mario Manningham and A.J. Jenkins at wide receiver, Brandon Jacobs and LaMichael James at running back, and quarterback Josh Johnson. That’s a good thing, because the 49ers are very unlikely to get a bye this season without significant improvements on offense.

  1. In both cases, pro-rated for 16-game seasons []
  2. Harbaugh would also be quick to point out that the team was also disadvantaged by being forced to play an elite team on the East Coast on just three days rest. []
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