How are these numbers calculated?

Big Games

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

Week of 10/10100.0*Chance in playoffs100.0*Average seed
Real Salt Lake 0 Portland 1 +28.0
+1.0
Week of 10/16100.0*Chance in playoffs100.0*Average seed
Galaxy 2 Portland 5 +23.9
+1.1
Earthquakes 1 Sporting KC 0 -11.8
-0.1
Sporting KC 0 Rapids 2 +1.1
+0.2
Dynamo 1 Seattle 1 -0.2
+0.1
Week of 10/25100.0*Chance in playoffs100.0*Average seed
Seattle 3 Real Salt Lake 1 -3.0
-0.4
Sporting KC 2 Galaxy 1 -3.0
-0.3
FC Dallas 2 Earthquakes 1 In
+0.1
Portland 4 Rapids 1 In
+1.3
Vancouver 3 Dynamo 0 -0.3
Points
Chance Will Make Playoffs