What's the probability that an NFL team with a given win/loss record makes the playoffs?

What's the probability that an NFL team with a given win/loss record makes
the playoffs?

For example, if I know that a team has a record of 11 wins and 5 losses,
but no nothing about the records of any other teams, what is the
probability that this team makes the playoffs?
The current (simplified) NFL rules for playoffs are that the team must
either have the best record in its division (three other teams), OR have
one of the best two records among teams in the conference that did not win
the division.
So I suppose what I'm trying to figure out is:
What is the probability that at least one out of three teams has a better
win-loss record? This is easy if I assume that the win/loss records of
each team in the division are independent (they aren't because each team
plays each team in the division twice), but how inaccurate will that make
the final answer?
What is the probability that at least two other teams had a better
win/loss record, but did not win their division? I really have no idea
where to begin with this. Again, the odds of two teams having a better
win/loss record is easy, but I'm not sure how to incorporate them winning
their division.
(I mentioned 11-5 as an example record, but really I'm trying to solve
this in general for any number of wins/losses, teams in a division,
divisions, and teams in a conference)