Definition
A power rating is a team strength number used to make point spreads. If each team is rated in points, the basic formula is:
Projected spread = Team A rating - Team B rating + home-field adjustment
A higher rating means the team is stronger. The number is not a prediction of the final score by itself. It becomes useful when compared against another team’s rating and the game location.
Worked Example
Say Kansas City is rated 27.5 and Denver is rated 23.0. On a neutral field:
27.5 - 23.0 = 4.5
Kansas City would project as a 4.5-point favorite. If Kansas City is at home and the home-field adjustment is 1.5 points:
4.5 + 1.5 = 6.0
The bettor’s projected line is Kansas City -6. If the sportsbook posts Kansas City -3.5 at -110, the bettor is comparing a six-point projection to a market spread of 3.5 points. At -110 odds, a $110 bet wins $100 before considering sportsbook hold or the bettor’s own error risk.
Why It Matters
Power ratings help a bettor compare personal numbers against the market before betting a spread. The concept is most useful when ratings are updated consistently and the gap between projected line and posted line is large enough to matter.