How are these numbers calculated?

Big Games

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

Week of 5/7100.0*Average seed
Bournemouth 1 West Brom 1 -0.5
West Ham 1 Swansea City 4 -0.2
Crystal Palace 2 Stoke City 1 -0.2
Week of 5/15100.0*Average seed
Manchester United 3 Bournemouth 1 -0.5
Southampton 4 Crystal Palace 1 +0.1
West Brom 1 Liverpool 1 -0.1
Watford 2 Sunderland 2 -0.0
Everton 3 Norwich City 0 -0.0
Points
Chance Will Win Championship