GREEN BAY, Wis. -- Walk down the hallway of Lambeau Field's third floor, where the Green Bay Packers coaches work, and one thing quickly becomes apparent: The doors are always open.

James Campen, who coaches the offensive line, might be in running back coach Ben Sirmans' office to discuss the blocking schemes on a run play. Cornerbacks coach Joe Whitt could be found in outside linebackers coach Winston Moss' office to talk about marrying coverages to zone blitzes.

There's cross-pollination as well. Defensive coaches will pick the brains of the offensive staff and vice versa.

"We call it 'across the hall,'" Packers coach Mike McCarthy says.

This offseason, McCarthy and his staff spent more time than ever before "across the hall."

Just days before they left for the NFL scouting combine in Indianapolis, the Packers coaching staff completed the most extensive self-scouting project that McCarthy has undertaken since he took over as head coach in 2006.

This wasn't the same old, same old, where the offensive coaches grade their own players and examine their tendencies, and the defensive coaches do the same with their guys. No, this was self-scouting to an extreme.

"The offense and defense took all 19 games and put it through a full breakdown like we were getting to play each other," McCarthy said. "We did a 19-game breakdown."

From Week 1 in Jacksonville to the NFC Championship Game loss in Atlanta, everything was on the table. McCarthy wanted to know exactly how another team would prepare to shut down his own team.

"Never done that," McCarthy said. "We've talked about it."

A two-week process

Every offseason begins the same way for McCarthy: exit meetings with the players before they leave town, performance reviews with his assistant coaches, and contract extensions with current and new hires.

And then it's time to get down to serious football.

McCarthy devoted two weeks of the offseason to his new study.

It started on Monday, Feb. 13. Week 1 was preparation. The offensive coaches studied, analyzed and critiqued defensive coordinator Dom Capers' side of the ball, while Capers' coaches did the same with the Packers' McCarthy-led offense.

Week 2 was presentation time. One by one, coaches stood in front of the rest of the staff and relayed what they discovered. In the morning session, an offensive coach "attacked the defense," as McCarthy put it. In the afternoon, it was the defense's turn. And on it went for the full work week, until the last presentation on Friday, Feb. 24.

"The conversations that it created were outstanding," McCarthy said. "The sharing of presentations, philosophies, the adjustments -- not only what the adjustments are but why you'd make that adjustment -- what it did for the football IQ and the development of our young coaches, it was a great exercise. It gave us a chance to [go] back and evaluate everything we did during the season, from scheduling, meetings, walk-throughs, and to do it right when it was fresh like that."

Check your ego at the door

The sessions weren't for the meek, but McCarthy believes that's one of the benefits of coaching in the same place for going on 12 seasons.

"We're a staff that's been together for a long time; we've been doing a lot together," McCarthy said. "But yeah, you better check the egos at the door."

McCarthy said he gave the coaches the same seven principles to be covered in every presentation. Although he did not want to reveal too many specifics, he did offer a rough outline of what he wanted.

"I want to know what the strengths were, what the weaknesses are, the tendencies, the mannerisms and so on," McCarthy said. "There was a consistency at how you were looking at each other within the game-plan structure that we use."

McCarthy has been at this so long and has been so successful that he probably could devise a game plan blindfolded. Yet he's said many times that he'll never just reach into the archives, pull out an old plan and change the date.

So there was McCarthy at the combine earlier this month, just days after the two-week project was completed, feeling better than ever about his staff's offseason work.

He wasn't the only one. One of his longtime assistant coaches said at the combine, "It's the best project we've ever done as a staff."

"As a coaching staff, I feel great about the first month that we've had," McCarthy said. "I think we're off to a really, really good start at improving and getting better."