How are these numbers calculated?

Big Games

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

Week of 7/29100.0*Average seed
Souths 24 St George 26 +0.4
Norths 20 Wests 16 -0.2
Gold Coast 14 Easts 38 -0.1
Parramatta 22 Brisbane 14 -0.1
Week of 8/5100.0*Average seed
St George 0 Canterbury 26 -0.3
Canberra 26 Easts 18 +0.1
Norths 12 Parramatta 6 -0.0
Week of 8/12100.0*Average seed
Newcastle 38 Norths 6 +0.1
Cronulla 16 St George 14 -0.1
Games Above .500
Chance Will Make Playoffs