Adjusting Your Ratings During The Season
You will have adjustments to make on a week-to-week basis. You will generally make these adjustments based on the performances of teams, and revelations that come about as a result of those performances. If a team performs in a manner which dictates that they are not as strong as their power rating would indicate, you can adjust the rating DOWNWARD. If a team shows that they are stronger than your previous estimation, you can adjust their rating UPWARD.
Do not do this in a rash manner. If a team gets blown out in a game, dont feel obligated to drop them ten points in your power ratings. By the same token, if a team pulls off a big upset, thats no reason to go hog-wild on them. Teams which are awful do not all of a sudden become good teams in a weeks time. And good teams do not all of a sudden become bad teams. You will make the minor adjustments (a point or two) on some teams from week-to-week, incrementally, according whether a teams performance indicates they should be rated slightly better or worse. When a team shows a very definite pattern of sub par performance, its appropriate to drop them by a more considerable increment.
But if you are going to err, do it on the side of caution. For example, everyone knows that the Baltimore Ravens were a playoff team in the 2010 season. And they have been a consistent performer under Jim Harbaugh. In the first game of the 2011 season, they forced seven Pittsburgh turnovers and routed the defending AFC champion Steelers 35-7. That was NOT a time to go overboard in upgrading them in a power rating. Just the same, after Baltimore lost the second game of the season to a Tennessee squad that did not seem like it was playoff-caliber, that isn't a spot to get down on them either. Don't overreact, and always put more stock in your adjustments on power ratings when you have more hard evidence to go by, which happens as the season progresses.