NASCAR has revamp their playoff format. Why can't The NFL change?

NASCAR will make the most extensive changes to its split-season playoff format since the Chase for the Sprint Cup was introduced in 2004, expanding the Chase field from 12 to 16 drivers and emphasizing winning races.

For more copy and paste the link below:

http://espn.go.com/racing/nascar/cup/story/_/id/10376863/nascar-makes-big-changes-chase-playoff-format