How are these numbers calculated?

Big Games

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

Week of 11/19100.0*Chance in playoffs100.0*Average seed
Matt 73 Keith 57 +0.6
+0.6
Chelsea 62 Jordan 99 +0.5
Nathan 92 Stephen 107 -0.4
+0.0
Tom 56 Tom O 69 -0.1
-0.1
Dan 60 Justin 60 -0.0
Week of 11/26100.0*Chance in playoffs100.0*Average seed
Justin 47 Matt 10 Out
-0.5
Stephen 124 Tom 89 Out
-0.1
Tom O 123 Chelsea 74 +0.4
-0.1
Nathan 73 Dan 80 +0.1
Week of 12/3100.0*Chance in playoffs100.0*Average seed
Jordan 84 Matt 91 +0.2
Justin 65 Nathan 97 +0.2
Games Above .500
Chance Will Make Playoffs