How are these numbers calculated?

Big Games

How we did last week and who we should root for this week.   Explain

Week of 1/27100.0*Chance wins title100.0*Average seed
Milford 5 Brighton 25 +1.4
+0.4
Brighton 24 South Lyon East 6 +1.3
+0.5
South Lyon East 11.5 Howell 18.5 -1.2
+0.1
Pinckney 19 Hartland 11 +0.2
Milford 2 Pinckney 28 -0.1
Week of 2/4100.0*Chance wins title100.0*Average seed
Howell 28 South Lyon 2 -3.5
South Lyon East 6 Brighton 24 +2.1
+0.4
Hartland 27 South Lyon East 3 -0.4
-0.1
Hartland 10 South Lyon 20 +0.1
Pinckney 24 Milford 6 -0.1
Week of 2/10100.0*Chance wins title100.0*Average seed
Pinckney 17 Brighton 13 No
-0.3
Brighton 14 Hartland 16 -0.6
Brighton 3 Howell 27 -0.3
South Lyon East 2 Pinckney 28 -0.2
Games Above .500
Chance Will Win Championship