How are these numbers calculated?

Big Games

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

Week of 11/6100.0*Chance in playoffs100.0*Average seed
Witcraft 10 Schoolman 6 +5.4
K. Jackson 5 Scheck 8 -1.3
-0.0
Hartman 10 Kato 3 -0.6
Zwiefel 9 M. Jackson 4 +0.5
Week of 11/20100.0*Chance in playoffs100.0*Average seed
Chick 7 Scheck 6 +62.6
+2.0
Zwiefel 7 Schoolman 11 -4.2
+0.7
Witcraft 11 Kato 5 +2.8
-0.2
Games Above .500
Chance Will Make Playoffs