A big part of getting an edge in NFL betting against the spread — one of the most difficult markets in sports due to how much work the sportsbooks put into getting the lines right with the eyes of the world watching — is being ahead of the market when it comes to team strength evaluation. If the market thinks the Giants are a 7-10 team, but you think the Giants are a 10-7 team and you're right, you're going to find value betting on the Giants until the market catches up. If you identify a fatal flaw in a supposed Super Bowl c ontender in Week 1 and adjust before the market, you can find great value fading that team for at least a few weeks.
Having a system in place to put a value on each team and then adjusting those values week to week is especially helpful early in the year before consensus builds on each team, and it continues to be useful throughout the season as injuries pile up, changes to coaching staff and key starters happen, and so on. That system is NFL betting power ratings.
What are power ratings? Well, anyone who has followed football (or really any sport) for any length of time has encountered a power rankings list that projects teams from best to worst. Where power ratings for NFL betting differs is that you're affixing a point total to each team that tells you how much better or worse it is from an average team. For example, if you think the Patriots are the midpoint of the league, their power rating would be a zero. If you think the Cardinals are a little bit better, yo u'd make them a +1. The Broncos may be another step above and worth a +2 rating. Going the other way, you may think the Browns are a -1 or -2 team with Jacoby Brissett at quarterback.
After you've rated all 32 teams in this fashion, you can take the difference between two teams in a scheduled matchup to determine what the line would be on a neutral field. In our example above, we'd say the Broncos should be favored by two points against the Patriots on a neutral field. Then you add in home field advantage, which for a long time was considered three points as a standard but is actually lower on average in this era of football. I actually determine unique home field advantage totals for each team based on data from the last five years, and you can find my breakdown of this year's home-field advantage ratings here.