NFL Week 6 upset picks: How the 49ers beat the Rams

Kyle Terada/USA TODAY Sports

How much weight do we give to a team's early performance, and how much weight do we give to what we knew about that team before the season? Those percentages change gradually as we get more information about how good teams are this season, but after five weeks, we're still asking the question.

That's important to remember when it comes to this week's game between the undefeated San Francisco 49ers and the 3-2 Los Angeles Rams. Based on what we know from this season, the current line that favors the Rams by three points doesn't make any sense. How much do you need to consider prior performance to see these teams as equal right now?

Upset Watch: San Francisco 49ers (+3) at Los Angeles Rams

Right now, the 49ers rank No. 1 in the Football Outsiders DVOA (Defense-adjusted Value Over Average) ratings, based on the first five weeks of the season, which include opponent adjustments for their easy schedule. Based on our ratings, the 49ers have been 58% more efficient than an average NFL team this season. The Rams, after last week's close loss to Seattle, have dropped to 17th. They come out as 1.3% more efficient than an average NFL team this season.

Of course, this early in the season, these are not the only numbers we use to analyze teams. We have a rating we call "DAVE" that combines early-season performance with our preseason projections. The preseason forecast had the Rams, coming off a Super Bowl season, as a much better team than the 49ers. Nonetheless, the DAVE rating also has San Francisco (26%) much higher than the Rams (8%). Our preseason forecast counts as 55% of this number for San Francisco and 45% of this number for the Rams (they have played one additional game).