How are these numbers calculated?

Big Games

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

Week of 4/15100.0*Chance in playoffs100.0*Average seed
Duluth High Sch 2 Meadowcreek Hig 0 -42.0
-1.4
Mountain View H 0 Habersham Centr 4 -5.7
-0.3
North Gwinnett 0 Mill Creek High 1 -0.7
-0.0
Mill Creek High 2 Peachtree Ridge 0 +0.2
Week of 4/18100.0*Chance in playoffs100.0*Average seed
Habersham Centr 1 Duluth High Sch 2 +0.1
Peachtree Ridge 2 Norcross High S 1 -0.2
Norcross High S 2 Duluth High Sch 5 +0.1
Collins Hill Hi 0 Peachtree Ridge 3 -0.0
Points
Chance Will Make Playoffs