How are these numbers calculated?

Big Games

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

Week of 3/10100.0*Chance in playoffs100.0*Average seed
Wales 22 Ireland 9 -0.9
-0.9
Week of 3/11100.0*Chance in playoffs100.0*Average seed
Italy 18 France 40 -0.6
-0.1
England 61 Scotland 21 +0.0
Week of 3/18100.0*Chance in playoffs100.0*Average seed
France 10 Wales 18 -9.2
-0.1
Ireland 13 England 9 In
+1.7
Scotland 29 Italy 0 -0.5
-0.1
Games Above .500
Chance Will Make Playoffs