How are these numbers calculated?

Big Games

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

Week of 3/6100.0*Average seed
Used To Be Good 49 Size Matters 47 +0.1
Week of 3/13None
Week of 3/20100.0*Average seed
Migos 58 Used To Be Good 48 -0.1
Games Above .500
Chance Will Win Championship