Your number vs. the line
How to Make Your Own Betting Lines: A Simple NFL Power Rating for Week 6
To make your own betting lines, give each team a power rating in points against an average team. Add a home field adjustment, adjust for key injuries, then subtract one rating from the other. The result is your spread. Write it down before you look at the line.
A simple rating you keep honest beats a complicated one you never check.
Why does your own number matter in a week like this?
Look at Chargers at Chiefs in Week 6. Kansas City opened as a 2.5-point favorite and moved to -8.5, according to RotoWire on Oct. 14. That move crossed 3, 6, and 7, all key numbers in NFL spread betting. On Thursday morning, Oct. 15, ESPN's game page still listed Kansas City -8.5.
RotoWire put it plainly: "You could have loved Kansas City at -2.5 and want absolutely nothing to do with the Chiefs at -8.5."
That is the case for making your own lines. Liking a team is not a bet. A bet is a team at a price, and you can only judge the price if you have a number of your own. Here is why you should set your own number before you see the line.
What is an NFL power rating?
A power rating is one number per team that says how many points better or worse it is than an average team on a neutral field. An average team is 0. A team rated +4 would be favored by about 4 points over an average team on a neutral field. A team rated -3 would be about a 3-point underdog.
Ratings are your best estimates, written down so you can test them.
How do you build a starter power rating?
- Rate every team in points against an average team. Start with how each team has played, and against whom. Keep the ratings in a range that makes sense, with most teams within a few points of 0.
- Write down why. One line per team. "Strong pass rush, weak offensive line" is enough. This is what you will check later.
- Update a little each week. Move a rating by a point or so after new information, not by five points after one result.
How do you adjust for home field?
Home teams get a small boost. A point or two is a common rough adjustment, but the right size is debated and changes over time. Pick a value, use it every week, and check it against the closing line over a season. Do not treat any home field number as a fixed fact.
How do you adjust for injuries?
Most single injuries move a rating very little. Quarterback is the big exception. Several injuries in the same group, such as two or three offensive linemen, can add up even when no single one matters much.
Adjust the team's rating for that game only, and write down what you changed.
How do you turn ratings into a spread?
Subtract the away team's rating from the home team's rating, then add your home field adjustment. The result is your spread for the home team.
Example only. These ratings are made up to show the math. They are not ratings for any real team, and this is not a pick or a prediction.
- Team A (home) is rated +2.0.
- Team B (away) is rated +1.0.
- Home field adjustment used in this example: 1.5 points.
- Team B's starting quarterback is out, so you lower Team B by 2.5 points for this game, to -1.5.
Your spread: 2.0 minus (-1.5) is 3.5, plus 1.5 for home field, for Team A -5. Write down "Team A -5" before you open any odds.
How do you compare your number to the line?
Now look at the line. If it is close to your number, passing is a perfectly good outcome. If the line is far from your number, ask what you might have missed before you think about betting.
Watch the key numbers. Field goals and touchdowns make 3 and 7 common final margins, so a line on the other side of 3 or 7 from your number is a bigger gap than the raw points suggest. Tag the game BET, WATCH, or PASS based on rules you set ahead of time.
How do you know if your ratings are any good?
Grade them against the closing line, not the final score. If your numbers keep landing near the close, your ratings are doing their job. Closing line value does not mean a bet won, and it does not promise a profit. Read more in What Is Closing Line Value (CLV)?, and here is how to track sports bets so that record builds up every week.
BetSharper is a journal built for this: write your number before you see the line, log the line and the close, and see over time how your ratings hold up. It is a self-awareness tool, not treatment. Start your journal at betsharper.ai.
Common questions
How do you make your own betting lines? Rate each team in points against an average team, add a home field adjustment, adjust for injuries, and subtract the away rating from the home rating. That result is your spread.
What are NFL power ratings? A power rating is a number for each team showing how many points better or worse it is than an average team on a neutral field.
What should I do if my number matches the line? Usually pass. A line close to your number means there is no gap to act on. Log the pass and grade your number against the close.
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BetSharper is a journal for your own numbers. It doesn't take bets and doesn't promise results.