How are these numbers calculated?

Big Games

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

Week of 4/10100.0*Chance in playoffs100.0*Average seed
Nacional 2 Velez Sarsfield 0 -19.5
-0.6
Emelec 1 Internacional 2 +0.9
-0.0
Week of 4/18100.0*Chance in playoffs100.0*Average seed
Internacional 1 Nacional 0 -31.8
-0.1
Velez Sarsfield 1 Emelec 0 In
+0.6
Week of 4/24None
Points
Chance Will Make Playoffs