How are these numbers calculated?

Big Games

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

Week of 10/7100.0*Chance in playoffs100.0*Average seed
Sounders 2 Wizards 1 In
+0.4
Earthquakes 2 DC United 0 -0.5
-0.2
Rapids 2 FC Dallas 2 +0.0
Week of 10/15100.0*Chance in playoffs100.0*Average seed
Dynamo 1 Earthquakes 0 +0.1
FC Dallas 0 Real Salt Lake 2 +0.1
Rapids 3 Galaxy 1 -0.1
Week of 10/21100.0*Chance in playoffs100.0*Average seed
Chivas USA 0 Earthquakes 3 -0.1
Points
Chance Will Make Playoffs