How are these numbers calculated?

Big Games

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

Week of 6/8100.0*Chance wins title100.0*Average seed
Canada 36 Tonga 27 +22.9
+0.3
USA 9 Tonga 18 -0.2
Week of 6/19100.0*Chance wins title100.0*Average seed
Japan 16 Canada 13 -64.0
-0.6
Fiji 35 USA 10 -0.2
Week of 6/23100.0*Chance wins title100.0*Average seed
Fiji 34 Tonga 21 -29.8
-0.3
Games Above .500
Chance Will Win Championship