How are these numbers calculated?

Big Games

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

Week of 5/1100.0*Chance wins title100.0*Average seed
Lazio 0 Inter Milan 2 -18.1
-0.2
Parma 1 AS Roma 2 +16.3
+0.2
Week of 5/9100.0*Chance wins title100.0*Average seed
Inter Milan 4 Chievo 3 -11.2
-0.1
AS Roma 2 Cagliari Calcio 1 +11.0
+0.1
Week of 5/15100.0*Chance wins title100.0*Average seed
Chievo 0 AS Roma 2 +26.6
+0.3
AC Siena 0 Inter Milan 1 No
-0.2
Points
Chance Will Win Championship