How are these numbers calculated?

Big Games

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

Week of 4/14100.0*Average seed
Yate Town 1 Slimbridge 1 -0.3
Yate Town 0 Totton 1 -0.3
Kidlington 1 Bideford 2 +0.2
Kidlington 0 Salisbury 1 +0.1
Kidlington 1 Swindon Superma 1 +0.0
Winchester City 0 Taunton Town 5 +0.0
Swindon Superma 1 Winchester City 1 -0.0
Didcot Town 0 Totton 0 -0.0
Week of 4/21100.0*Average seed
Paulton Rovers 2 Yate Town 0 -0.3
Larkhall Athletic 1 Yate Town 0 -0.3
Cinderford Town 2 Bristol Manor F 0 -0.2
Cinderford Town 3 Bideford 4 +0.2
Kidlington 3 Shortwood United 0 -0.1
Larkhall Athletic 0 Cinderford Town 1 -0.1
Cirencester Town 3 Kidlington 2 +0.1
Winchester City 2 North Leigh 0 -0.0
Week of 4/28100.0*Average seed
Yate Town 2 Bishop's Cleeve 0 +0.4
Kidlington 2 Mangotsfield Un 2 +0.2
Cinderford Town 2 Taunton Town 3 +0.2
Shortwood United 0 Kidlington 5 -0.1
Points
Chance Will Make Playoffs