How are these numbers calculated?

Big Games

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

Week of 4/24100.0*Chance wins title100.0*Average seed
Port Vale 2 Notts County 1 +2.6
Hereford 2 Rochdale 1 -1.7
Darlington 0 Notts County 5 No
Week of 5/8100.0*Chance wins title100.0*Average seed
Barnet 1 Rochdale 0 -0.4
Chesterfield 2 Bournemouth 1 +0.3
Points
Chance Will Win Championship