Seattle Seahawks Playoff Chances 2013-2 50/50

Beat St. Louis 27-9, average seed up 1 to 1
13-3-0   .813

How are these numbers calculated?

Big Games

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

Week of 12/12100.0*Average seed
Seattle 23 NY Giants 0 +0.4
San Francisco 33 Tampa Bay 14 -0.3
St. Louis 27 New Orleans 16 +0.1
Week of 12/22100.0*Average seed
San Francisco 34 Atlanta 24 -0.5
Arizona 17 Seattle 10 -0.2
Week of 12/29100.0*Average seed
San Francisco 23 Arizona 20 -1.0
Seattle 27 St. Louis 9 +1.0
Games Above .500
Chance Will Make Playoffs