How are these numbers calculated?

Big Games

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

Week of 9/13100.0*Chance in playoffs100.0*Average seed
Revolution 3 Tampa Bay 0 -22.2
-1.0
Tampa Bay 2 New York 1 +17.9
+0.8
DC United 1 Miami 3 -13.1
-0.3
Miami 4 DC United 3 -8.1
-0.2
New York 0 DC United 5 +0.2
Dallas 1 Earthquakes 3 -0.1
Earthquakes 0 Galaxy 0 +0.0
Week of 9/20100.0*Chance in playoffs100.0*Average seed
Crew 3 Tampa Bay 4 +23.0
+1.3
Fire 3 Revolution 2 +6.0
+0.3
Galaxy 0 Earthquakes 1 -0.2
Revolution 0 New York 0 +0.2
Rapids 3 Dallas 1 +0.1
Week of 9/27100.0*Chance in playoffs100.0*Average seed
Miami 1 Tampa Bay 3 In
+2.1
Earthquakes 2 Wizards 0 -0.2
Points
Chance Will Make Playoffs