How are these numbers calculated?

Big Games

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

Week of 4/4100.0*Chance in playoffs100.0*Average seed
Winder Barrow H 0 Clarke Central 4 -45.0
-0.9
Winder Barrow H 2 Apalachee High 3 -27.8
-0.8
Week of 4/12None
Week of 4/18100.0*Chance in playoffs100.0*Average seed
Flowery Branch 1 Cedar Shoals Hi 0 -7.7
-0.2
Heritage High S 5 Loganville High 2 Out
Apalachee High 5 Flowery Branch 3 +1.0
+0.3
Points
Chance Will Make Playoffs