Don Coryell was a mentor to Hall of Fame coaches Joe Gibbs and Mike Martz. They were tutored by the offensive genius in the sui generis fine art of the modern passing game. The Chargers, the Redskins and the Rams (respectively) were among the absolute highest-scoring offenses in NFL history.
The "Air Coryell" passing attack featured deep timing routes and multiple receiver sets with motion to confuse and overwhelm defenses. Dan Fouts, Joe Theisman and Kurt Warner are some of the Hall of Fame QBs whose success is owed in part to the trail which Don Coryell blazed.
Don Coryell is a finalist to be in the Hall of Fame for the first time this year. It's a shame he won't be able to accept the award in person. He was 85.
Very fine article about the coaching relationship Gibbs and Coryell had, if you're interested.
*sui generis = of its own kind, unique. I thought you went to college?