How are these numbers calculated?

Big Games

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

Week of 7/30100.0*Chance in playoffs100.0*Average seed
Southern 2 Botany 3 -16.6
-0.3
Dunedin 5 Canterbury 7 -7.8
-0.1
Dunedin 4 Canterbury 7 -5.8
-0.1
Week of 8/6100.0*Chance in playoffs100.0*Average seed
West Auckland 5 Southern 3 +41.5
+0.4
West Auckland 6 Southern 3 +37.5
+0.7
Canterbury 6 Botany 1 -20.2
-0.2
Canterbury 13 Botany 4 -4.7
+0.1
Week of 8/13100.0*Chance in playoffs100.0*Average seed
Dunedin 2 West Auckland 0 Out
-0.8
Dunedin 2 West Auckland 8 +20.2
+0.2
Points
Chance Will Make Playoffs