Question For Sharps, How Do You Make Your Own Line?

Question For Sharps, How Do You Make Your Own Line? I am fairly new to sports betting and was hoping some of the forum sharps could answer a question. How do you come up with your own line for a college or pro football game? Do you use offensive/defensive stats, past trends, home field advantage (3 points), travel etc? Thanks.
Formula I make NFL power ratings which represents the games a team would win vs. an average schedule if the season was started that day. Ok to just use the current season wins numbers right now. (SEASON WINS TEAM A-SEASON WINS TEAM B)*2.5 is a neutral field line. Adjust 3 for home field. If you come up with a spread over 6, you need to bring it back by about 1/3 for every point over 6
sweet info Fezz, thanks.
[QUOTE=Fezzik;2614]I make NFL power ratings which represents the games a team would win vs. an average schedule if the season was started that day. Ok to just use the current season wins numbers right now. (SEASON WINS TEAM A-SEASON WINS TEAM B)*2.5 is a neutral field line. Adjust 3 for home field. If you come up with a spread over 6, you need to bring it back by about 1/3 for every point over 6[/QUOTE] ok how do you figure what the teams win would be then over what is a average schedule how is the average schedule figured out

With so much parity in the NFL, just use their season win numbers..... Not much difference between a moderately hard vs. easy schedule
What about totals?
THAT is gonna take more time......... Totals are complicated
My math skills aren't great, but here goes Team A (Home) 12 Wins - Team B 6 Wins = 6 * 2.5 = 15 + 3 Home = 18 11 Points over 6 = 11/3 = 3.6 Line = 14
Math Correction [QUOTE=grux;2730]My math skills aren't great, but here goes Team A (Home) 12 Wins - Team B 6 Wins = 6 * 2.5 = 15 + 3 Home = 18 11 Points over 6 = 11/3 = 3.6 Line = 14[/QUOTE] 18 is 12 over 6 not 11 so adjustment is 4 (12/3=4) so Rating is 14 (18 -4 = 14, same as you got by rounding 3.6 to 4).
[QUOTE=MobileBandit;2742]18 is 12 over 6 not 11 so adjustment is 4 (12/3=4) so Rating is 14 (18 -4 = 14, same as you got by rounding 3.6 to 4).[/QUOTE] Thanks Mobile. I appreciate the correction.