How are these numbers calculated?

Big Games

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

Week of 4/20100.0*Relegated **100.0*Average seed
London Irish 47 London Welsh 28 No
+0.3
Worcester 26 Harlequins 42 +0.1
Northampton 47 Sale Sharks 7 +0.1
Week of 5/4100.0*Relegated **100.0*Average seed
London Welsh 33 Worcester 22 +0.3
Leicester 32 London Irish 20 -0.1
Sale Sharks 21 London Wasps 20 -0.1
Games Above .500
Chance Will Make Playoffs