Position backgrounds of current coaches

NASHVILLE, Tenn. -- The Tennessee Titans' last head coach, Mike Munchak, jumped from offensive line coach to head coach.

Where will the guy who replaces him come from?

So far, the candidates are all coordinators in the NFL. But I was curious where head coaches in the NFL originated. What positions did they coach before they moved up the ranks?

Some moved around a lot, some worked exclusively at one spot. Some were tougher to categorize than others and I leaned a bit on what they played if I was tie-breaking.

My breakdown of the NFL coaches who were in the league in 2013 and remain in their posts:

Quarterbacks (7): Mike McCoy (Broncos), Bruce Arians (Cardinals), Marc Trestman (Bears), Jason Garrett (Cowboys), Mike McCarthy (Packers), Sean Payton (Saints), Jim Harbaugh (49ers).

Defensive backs (6): John Fox (Broncos), Chuck Pagano (Colts), Dennis Allen (Raiders), Mike Tomlin (Steelers), Jeff Fisher (Rams), Pete Carroll (Seahawks).

Linebackers (5): Marvin Lewis (Bengals), Gus Bradley (Jaguars), Bill Belichick (Patriots), Mike Smith (Falcons), Ron Rivera (Panthers).

Offensive line (3): Doug Marone (Bills), Andy Reid (Chiefs), Joe Philbin (Dolphins).

Defensive line (1): Rex Ryan (Jets).

Running backs (1): Chip Kelly (Eagles).

Special teams (1): John Harbaugh (Ravens).

The Titans' interviews so far were with two guys with a quarterback background in Jay Gruden (who's now off the market) and Jim Caldwell and one with a defensive backs background in Mike Zimmer. Next up is Ken Whisenhunt, who has a tight ends background.

Others who I think will be interviewed: Dan Quinn (defensive line) and Rich Bisaccia (special teams).