How are these numbers calculated?

Big Games

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

Week of 5/3100.0*Promoted100.0*Average seed
Brechin City 1 Stenhousemuir 3 -6.1
-0.3
Ayr United 4 East Fife 1 +5.6
+0.5
Stranraer 3 Forfar Athletic 1 +1.1
-0.2
Points
Chance Will Win Championship