How are these numbers calculated?

Big Games

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

Week of 5/28100.0*Chance in playoffs100.0*Average seed
Japan 15 Canada 39 +31.2
+0.6
Tonga 6 Canada 24 +17.1
+0.6
Tonga 35 Uruguay 20 -1.1
-0.0
Japan 40 Uruguay 20 -0.2
-0.0
Week of 6/5100.0*Chance in playoffs100.0*Average seed
Canada 36 Uruguay 15 Yes
+0.4
Japan 43 Tonga 22 -0.7
-0.0
Games Above .500
Chance Will Make Playoffs