I made some improvements to the power rankings this week. Let me explain some of my reasoning and method.
First, I decided that power rankings look at what teams have done and not what they will do so there is no projecting values. Second, these are totally unaltered rankings after I created a formula to judge a team's "power" compared to other teams.
The rankings have four components. The first two are Pro-Football-Reference.com's offensive and defensive simple rankings. When combined they for PFR's simple rating system. I chose to treat offense and defense separately for one reason: I think offense is far more important in today's NFL.
How much more important? After playing with the numbers and seeing how teams landed using different numbers I decided on 25 percent. That is, offense is 25 percent more important than defense. This is arbitrary, but it gave me results that I looked fair to me. These are my power rankings after all.