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
Brighton 28 South Lyon East 2 +0.1
+0.4
South Lyon 5 Hartland 25 +0.0
Milford 13 Brighton 17 +0.1
Pinckney 3 Hartland 27 +0.0
Milford 9 Pinckney 21 -0.0
Week of 2/4100.0*Chance wins title100.0*Average seed
South Lyon East 17 Brighton 13 -0.1
-0.5
Hartland 22 South Lyon 8 -0.0
Hartland 21 South Lyon East 9 +0.1
Pinckney 27 Milford 3 -0.0
Howell 28 South Lyon 2 +0.0
Week of 2/10100.0*Chance wins title100.0*Average seed
Pinckney 24 Brighton 6 -0.7
South Lyon 20 Brighton 10 -0.5
Pinckney 14 South Lyon 16 -0.2
Brighton 13 Howell 17 -0.1
South Lyon East 27 Pinckney 3 -0.1
Brighton 6 Hartland 24 -0.0
South Lyon 24 Milford 6 -0.0
Games Above .500
Chance Will Win Championship