They use point differential for the point spread then add 3 points to the home team. This math here is always within a point to start off.
Then they adjust the line according to where the money is going.
Denver +4 point diff.
Atlanta +.6 point diff, round up is one + 3.
Tie game advantage home team.
Boston +6.5 + 3 for the home team so Boston -11
Detroit -4.4 + 3
Pistons -5 should be the line
So you have the Heat by -7.
Just four examples but the math is there. You can find the point diff. on ESPN.
For totals, I believe the opposing opponent points allowed is used to create the line. But it can by off by 10 points because bettors tend to favor overs I believe. I know ten is a lot but I think when you know public is going to bet the over or under no matter what, you to adjust to make them think about.
Atlanta allow 95 p/g
Denver allows 104 p/g
I just sharing what I think. Open up discussion, see if there's a system that can be developed from this or a filter of some kind.
I dunno, just something I wanted to share