How are these numbers calculated?

Big Games

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

Week of 10/19100.0*Chance in playoffs100.0*Average seed
Island Trees 14 Seaford 41 +10.4
+0.6
CSH 14 Clarke 22 -1.3
-0.1
Oyster Bay 37 East Rockaway 70 -0.5
Friends 7 Locust Valley 24 -0.1
-0.0
Week of 10/26100.0*Chance in playoffs100.0*Average seed
Seaford 40 East Rockaway 8 In
+0.5
Carle Place 0 Island Trees 31 -0.3
West Hempstead 7 Locust Valley 40 -0.0
Malverne 6 CSH 45 -0.0
Week of 11/2100.0*Chance in playoffs100.0*Average seed
Locust Valley 0 Seaford 41 +0.9
Clarke 57 Oyster Bay 14 +0.0
Games Above .500
Chance Will Make Playoffs