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 +19.6
+0.7
Emelec 1 Internacional 2 -8.2
-0.1
Week of 4/18100.0*Chance in playoffs100.0*Average seed
Internacional 1 Nacional 0 -19.0
-0.7
Velez Sarsfield 1 Emelec 0 -2.7
-0.1
Week of 4/24None
Points
Chance Will Make Playoffs