Allen Park — It's difficult to maintain continuity in the NFL. If you're good at something for multiple years, the cost to maintain your best players often butts up against salary cap constraints, and your talented assistant coaches are going to be offered promotions to coordinator or head coach with other franchises.
The Seattle Seahawks have seen plenty of that over the years. The storied "Legion of Boom" secondary is all but gone. Cornerback Richard Sherman is in San Francisco, safety Earl Thomas is out for the year with an injury and already had a foot out the door due to contentious contract talks, and hard-hitting safety Kam Chancellor was forced into early retirement due to a neck injury.