While this doubles as a personnel-based trend, the Seahawks have declined in the years since they fired their defensive coordinator following the 2017 season. Gus Bradley and Dan Quinn rode dominant Seahawk defenses to HC gigs, and Richard finished off the team’s unprecedented (in the Super Bowl era, at least) four straight years with the No. 1-ranked scoring defense. In terms of total defense, the team finished fifth in 2016 and 11th in 2017, the latter despite season-ending Richard Sherman and Cliff Avril injuries. Seattle has ranked in the top 20 defensively once since. Stripping the unit of its non-Bobby Wagner cogs has mattered, but the post-Richard downhill slope persists.

The Steelers defensive coordinator during their Greg Lloyd-Kevin Greene “Blitzburgh” days in the mid-1990s, LeBeau returned after a failed stint as Bengals head coach. The Hall of Fame DB’s second act in Pittsburgh produced two Super Bowl trophies, with both the 2005 and ’08 Steeler champion teams geared around menacing defenses. Pittsburgh’s 2008 defense led the NFL in points, yards and DVOA. After a down 2014, the team’s first post-Troy Polamalu year, the Steelers and LeBeau mutually parted ways. The Steelers proceeded to become an offense-oriented team behind the “Killer B’s,” beginning a period of high sack numbers but consistent defensive unreliability.

Reid recently reminded the Eagles how valuable he has become in his second act, with he and prized pupil Patrick Mahomes beating a better (roster-wise) Philly squad in Super Bowl LVII. The Eagles’ steadiest Super Bowl-era period came under Reid, their HC from 1999-2012; Philly soared to five NFC championship games and a Super Bowl. But the 2011 “Dream Team” effort fizzled, leading to a 4-12 2012 season. The Eagles have enjoyed success post-Reid, winning Super Bowl LII. But Reid is now in the top five in all-time wins and has built a superpower in Kansas City. The Chiefs are 10-for-10 in winning seasons under the play-calling mastermind.