How are these numbers calculated?

Big Games

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

Week of 8/6100.0*Chance in playoffs100.0*Home Advantage100.0*Average seed
Southern 4 South Auckland 1 -25.6
No
-0.5
Week of 8/19100.0*Chance in playoffs100.0*Home Advantage100.0*Average seed
Canterbury 5 West Auckland 11 Out
-0.3
Points
Chance Will Make Playoffs