A murmur spread Wednesday afternoon, roiling the humdrum of another Ravens bye week.

As John Harbaugh outlined the broad strokes of Baltimore’s preparation for its divisional playoff game in another week and a half, phones were lighting up with NFL news: Pete Carroll was out in Seattle. A reporter shared the news with Harbaugh as he walked away from the podium, and the Ravens coach admitted he was “stunned.”

There was about to be a lot more news in the coaching world, shifting the ground beneath our feet.

Within 24 hours, Nick Saban — who had a forgettable NFL tenure but was an unmatched winner in college football — had retired, and Bill Belichick — the all-time leader in Super Bowl wins, all the while wearing an immutable scowl and an iconic hoodie — was out in New England.

The thing about climbing the ladder is you never know how many rungs are ahead of you. Even as an NFL coach, Harbaugh has been steadily gaining experience and esteem, fielding consistent winners with a championship to boot.

Suddenly, he’s at the top. There are no more rungs left.

On Wednesday morning, there were four NFL coaches who had been with their teams at least 14 seasons. A day later, Carroll and Belichick were gone, leaving just Pittsburgh’s Mike Tomlin (who was hired in 2007) and Harbaugh (hired a year later). The next closest is Andy Reid, who has been in Kansas City since 2013. Reid, of course, spent 14 seasons with the Philadelphia Eagles before that and was at one point Harbaugh’s boss.

Then there’s a three-way tie for coaches hired in 2017, illustrating just how tenuous a head coach’s job security is.

Looping in Saban, who has coached a number of great players who have passed through Baltimore, some of the most venerated coaches on the sport’s Mount Rushmore crumbled in a single day.

Harbaugh still has the energy of the 45-year-old Baltimore once hired, but he’s far along enough in his career to acknowledge that his 61 years are creeping up on him. Last week, as the Ravens prepared for a low-stakes game against Pittsburgh, a reporter gracefully asked Harbaugh how on-field pregame conversations with Tomlin have evolved “from the beginning as you were both young coaches.”

A grin quickly spread across Harbaugh’s face. “I appreciate the ‘both young coaches!’”

Harbaugh technically may not remain one of the NFL’s elder statesmen for long. Belichick and Carroll, both in their 70s, might look for other opportunities. But what’s most remarkable about Harbaugh now right at the top: He’s still in his prime.

It may be his roots as a special teams coordinator, coming to Baltimore with the reputation of neither an offensive wunderkind nor a defensive mastermind, but Harbaugh has rarely seemed to get the credit for a team that has gone 160-99 in his tenure. He has won Associated Press Coach of the Year only once, in the electric 2019 season when Lamar Jackson won MVP. After a 13-4 season in which his Ravens demolished the Lions, 49ers and Dolphins among others, Harbaugh is receiving little buzz again — in spite of the fact that he’s replaced both coordinators since 2019, leaving him as the common coaching denominator.

Since Harbaugh was hired 16 years ago, nine other NFL coaches who have won coach of the year have been fired by (or, ahem, parted ways with) the teams they won with: Belichick, Mike Smith, Marvin Lewis, Jim Harbaugh, Bruce Arians, Ron Rivera, Jason Garrett, Matt Nagy and Mike Vrabel.

Harbaugh keeps doing his thing. He’s had a top-10 scoring offense seven times. He’s had a top-five scoring defense nine times. He’s had a losing regular season record only twice, and the Ravens only truly bottomed out once (2015). He’s coached all-time players, including Ray Lewis and Ed Reed and probably Jackson whenever his career is over, but Harbaugh’s career cannot be defined by one player in the way that Belichick, for all his greatness, will be forever linked with Tom Brady.

It helps, of course, when your front office drafts two good quarterbacks for you, and Harbaugh benefited from Joe Flacco and Jackson falling into Baltimore’s lap. The previous two years of injuries soured seasons at the end, and perhaps the Ravens hung on too long with Greg Roman, who limited the scope of the offense with “medieval” football.

But especially in light of the end of Belichick’s tenure, marked by clinging to familiar names such as Bill O’Brien and Joe Judge while steadily declining, Harbaugh’s willingness to evolve stands apart. He made two hires in the past two seasons that have fundamentally shifted the Ravens’ identity on both sides of the ball.

Mike Macdonald’s deceptive schemes are much less aggressive than Wink Martindale’s “damn the torpedoes and blitz” philosophy. Todd Monken has kept some of Roman’s running concepts but spread the offense out much more and thrown more often, unlocking a version of Jackson that many people believed was lying just underneath the surface. Both are now head coaching candidates, hunted by forlorn franchises that would like to chip off a piece of Baltimore’s magic.

Harbaugh never came in with a reputation for an offensive or defensive genius, and that’s turned out to be a strength. He is consistent in how he approaches and runs the Ravens on the field, but he can’t be pinned down to a single schematic style — an inherent reason he’s been able to change with the times. He is fluid, molding and adapting to his roster and the league, which is why the Ravens still feel at the cutting edge of the NFL despite having one of the league’s longest-tenured coaches.

Macdonald thinks Harbaugh “has a lot of superpowers,” but two key ones are his adaptability and a keen insight for how certain systems help or hurt.

”He can see systematically how things are wired and if it makes sense,” Macdonald said. “And so he’s really good at holding us accountable to how things are ruled out and where we’re going and making sure it makes sense and [that] it has enough. And he balances that.”

Added Macdonald: “And then I’d say he’s relentless. And I feel I share that quality, too. We’re constantly in pursuit of trying to help our guys out and trying to put our guys in situations where they can be successful. And, to me, if you’re not doing that, what are you doing?”

It’s always difficult to say how much credit a head coach deserves relative to his players and staff, but some telling endorsements come from the players themselves. On Brady’s podcast, Jackson said his relationship with Harbaugh has grown over the years and “we’re in sync with everything we do.” Odell Beckham Jr. said this season he texted Harbaugh to compliment him on how well run the organization is, and then after a win over Miami confessed to the locker room: “This is the best team I’ve ever been on, from the top to the bottom.”

If the bottom line falls to the head coach when things fail, a sizable portion of the credit should go to him when the team succeeds. And Harbaugh has succeeded more than most, enduring in a league where the coaching carousel always seems to be spinning. That’s thanks in part to owner Steve Bisciotti’s commitment to continuity but also to Harbaugh for making the decision easy.

Now that Harbaugh’s at the top of the ladder, the NFL’s young coaches are climbing to catch him. At this rate, it could take them a while to catch up.

Jonas Shaffer contributed reporting.