Week 1 Arizona was at home against the Saints. My estimated line of Arizona-2.5 was the same as the odds-makers line leaving no value on either side. Since it was below the key number of three, I felt like the Cardinals had a better than 51% chance of winning and covering the spread.
Arizona won 31-19. The difference was 9.5 points and that's the number you would look for on the green chart. The 9.5 points was 1 point added to Arizona and -1 point subtracted from the Saints power rating.
When figuring the spread range, use the same 9.5 difference and look it up on the blue chart. The chart show Arizona should be +4 which would be written down in Arizona's week 2 spread range column. The Saints are obviously -4 in their spread range column for week 2.
In week two, Arizona played the Bears on the road. The Bears were coming off a loss to Green Bay and had a power rating of 20.5. Arizona had a 1 point increase in their power rating, but lost the 2.5 home field advantage by going on the road, therefore making their power rating 22.
The spread range was only a 5 point difference and we are looking for a 10 point difference in order to play the dog. (+4, -1)=5 point difference. Your adding or subtracting down the team page column and carrying over your opponent spread range and then cross adding or subtracting those two numbers to check the difference.
Week 3 Arizona was +10 and San Francisco was zero. This was the first game to qualify as a possible spread range dog play. I didn't use it because that was the only thing pointing to San Francisco. Odds-makers gave me a 3 point edge with my power ratings and this was the 49ers 2nd of back-2-back games on the road.
Don't use the spread range alone. It's a good tool to support your power rating or 5 point move, but not so great as an only factor. If you look at week 4 against the Rams, we had the spread range qualify and the 5 point move to over-ride the power rating value.
If your a first time buyer, understanding the power rating and spread range up dates will make it easy to update and have your plays ready after the last game of every week.