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 +7.7
+0.1
Duluth High Sch 2 Meadowcreek Hig 0 +6.7
+0.1
Mountain View H 0 Habersham Centr 4 -5.5
-0.2
North Gwinnett 0 Mill Creek High 1 -0.1
Week of 4/18100.0*Chance in playoffs100.0*Average seed
Norcross High S 2 Duluth High Sch 5 In
+0.6
Collins Hill Hi 0 Peachtree Ridge 3 -36.3
-1.1
Habersham Centr 1 Duluth High Sch 2 +10.3
+0.1
Peachtree Ridge 2 Norcross High S 1 -3.5
+0.1
Points
Chance Will Make Playoffs