How are these numbers calculated?

Big Games

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

Week of 8/14100.0*Chance in playoffs100.0*Average seed
West Auckland 6 Canterbury 5 In
West Auckland 8 Canterbury 7 (ot)+23.5
Southern 3 Dunedin 4 (ot)-4.7
Southern 2 Dunedin 13 +0.8
Week of 8/21None
Chance Will Make Playoffs