How are these numbers calculated?

Big Games

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

Week of 4/19100.0*Chance in playoffs100.0*Average seed
Connacht 18 Ulster 34 In
+0.3
Glasgow 35 Ospreys 17 +0.1
-0.0
Zebre 22 Leinster 41 -0.0
Week of 4/26None
Week of 5/3100.0*Chance in playoffs100.0*Average seed
Ulster 37 Blues 13 +0.2
Leinster 37 Ospreys 19 -0.1
Connacht 3 Glasgow 20 -0.0
Games Above .500
Chance Will Make Playoffs