Just like when Greg Mattison replaced Rex Ryan in 2009, continuity was key in finding a successor to Mattison.
When Mattison took the same position with the University of Michigan this week, all Harbaugh had to do was look down the hall.
"It was an easy choice. It was quick," Harbaugh said Thursday. "I've known Chuck on-and-off for 20-some years, and I've always just admired what he's done and the way he's done it.
"Now to work with him for these three years closely and see how he does it, you know, I just have great admiration and respect for him. He's been instrumental in building this defense."
Pagano's promotion from secondary coach to coordinator marks his first professional coordinating post, having previously been a position coach with the Oakland Raiders and Cleveland Browns before joining the Ravens in 2008.
But despite his experience coordinating the defense at UNLV (1990-91) and North Carolina (2007), Pagano believes his experience in Baltimore is what's most important.
With players such as safety Haruki Nakamura, defensive tackle Haloti Ngata and linebacker Jarret Johnson in attendance at his press conference – along with Defensive Line Coach Clarence Brooks, Linebackers Coach Dean Pees, Outside Linebackers Coach Ted Monachino, Special Teams Coordinator Jerry Rosburg and Secondary Assistant Roy Anderson – Pagano took solace in the well-known faces he'll work with in the coming years.
"They've been very, very good over the years here because of continuity," said Pagano, whose secondary was solid in 2010 despite several injuries. "There's been guys walk out of the door and have opportunities and move on, which is great for them, but the thing that hasn't changed is the system, for the most part."
There have been some tweaks to the defense since Marvin Lewis' 4-3 unit won Super Bowl XXXV.
Styles change over the years – i.e. Rex Ryan's attacking, blitz-from-anywhere scheme – but Pagano thinks General Manager Ozzie Newsome adds personnel to fit the Ravens' mentality and the veterans pass it down.
Last season, the Ravens were the third-stingiest scoring defense (16.9 points allowed per game) even though Mattison was oft criticized for not blitzing enough.
"All the guys on our defensive side have played great football for a lot of years," noted Harbaugh. "And not just them – the guys that came before them who taught them, and the coaches, same thing, and you build on that.
"We talk about this all the time: It's not a 'Rex' defense, it's not a 'Greg' defense, it's not a 'John,' it's not a 'Chuck,' it's not an anybody. It's a Ravens' defense. We believe in team around here, and it starts with the players."
Harbaugh also needed to consider an uncertain labor situation that could find the NFL in a work stoppage after the Collective Bargaining Agreement expires on March 4.
If owners and the NFL Players' Association cannot reach a new agreement, clubs won't be allowed to hold offseason minicamps or organized team activities.
A brand new coordinator would also be severely limited in installing a new system.
"I think it's real key," said Ngata. "As players, it makes us more at ease because we know we're not going to see many new things, new philosophies, new terminologies. We know that he's going to pretty much try to keep it the same for us and make it easier to go out there and play."
Pagano said he will simply continue to put his stamp – however large or small – on the Ravens' defensive tradition.
The fact that he gets to coach a group he's been with for three years already just makes the transition easier – both for the Ravens and Pagano.
"The structure of the defense is basically the same, but the personality of the defense – the players playing the defense – that's never going to change," Harbaugh said. "I think when you promote from within – guys like Chuck – they understand that; they've been part of that.
"Now, we continue to grow and get better."