How are these numbers calculated?

Big Games

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

Week of 4/8100.0*Average seed
Winchester City 0 Larkhall Athletic 0 -0.2
Slimbridge 2 Bideford 0 +0.2
Didcot Town 2 Wimborne Town 0 +0.1
Paulton Rovers 3 Shortwood United 1 +0.1
Week of 4/15100.0*Average seed
Winchester City 0 AFC Totton 1 -0.8
Tiverton Town 1 Winchester City 0 -0.3
Shortwood United 1 Swindon 0 -0.3
Wimborne Town 0 Yate Town 3 +0.2
Larkhall Athletic 0 Didcot Town 1 +0.2
Taunton Town 0 Bideford 0 -0.1
Slimbridge 1 Shortwood United 2 -0.1
Salisbury 5 Wimborne Town 2 +0.1
North Leigh 1 Paulton Rovers 0 +0.0
Yate Town 2 Larkhall Athletic 2 +0.0
Week of 4/22100.0*Average seed
Larkhall Athletic 3 Swindon 1 -0.4
Hereford FC 4 Winchester City 0 -0.2
Tiverton Town 3 Paulton Rovers 1 +0.1
Wimborne Town 3 Slimbridge 1 -0.1
Points
Chance Will Win Championship