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
Mill Creek High 2 Peachtree Ridge 0 +3.5
+0.1
Duluth High Sch 2 Meadowcreek Hig 0 +1.0
+0.0
Mountain View H 0 Habersham Centr 4 -1.0
-0.0
North Gwinnett 0 Mill Creek High 1 -0.0
Week of 4/18100.0*Chance in playoffs100.0*Average seed
Norcross High S 2 Duluth High Sch 5 Out
-1.4
Peachtree Ridge 2 Norcross High S 1 -19.3
-0.9
Collins Hill Hi 0 Peachtree Ridge 3 -6.0
-0.0
Habersham Centr 1 Duluth High Sch 2 +5.4
+0.0
Points
Chance Will Make Playoffs