Detroit Lions head coach Jim Caldwell watches his team play against the Buffalo Bills during an NFL game at Ford Field in Detroit on Sunday, Oct. 5, 2014. (Jeff Haynes/AP Images for Panini)

When Lions head coach Jim Caldwell set about hiring an offensive coordinator in January, his ideal candidate needed to possess these qualifications above all others. He had to have a good understanding of offensive football; to have been around excellent quarterback play; and to have been in a system that utilized an array of weapons.