AS COACH BILL Belichick was turning the corner into the AFC coaches media breakfast at the NFL’s owners meetings, an annual tradition he generally loathes, a New England Patriots staff member handed him a square blue pin.

Belichick pinned it to his pink and gray checkered dress shirt, but in a most unusual spot: more than halfway down the left side by his ribs.

The NFL’s longest-tenured head coach then sat at a round table where eight to 10 media members and a television camera were waiting for him, and he begrudgingly answered questions about his team and the outlook for the 2023 season. Deep into the interview, he was asked about the pin.

“It’s Mr. Kraft’s initiative,” Belichick responded, speaking of Patriots owner Robert Kraft.

Your thoughts on the initiative?

“I support it,” Belichick answered.

That late-March morning exchange at the posh Arizona Biltmore might have been a subtle snapshot of a growing strain between Kraft and Belichick in their 24th year together as owner and coach.

Or maybe it was just Belichick being Belichick. He had skipped the coaches breakfast in the past, generally seeing little value in March interviews that fuel hype and isn’t one to willingly go along with NFL-driven initiatives involving the media.

Like many things involving Belichick, his intentions are a mystery.

A few hours after the breakfast with Belichick, Kraft stood proudly outside in the Arizona heat, reporters circled around him as the cacti and blazing Southwest sunshine provided a picturesque backdrop. He had the same blue pin affixed to the left side of his light blue dress shirt, easily visible between the second and third buttons, not far from the “RKK” initials embroidered slightly below it.

Before Kraft fielded questions, he spoke passionately about the meaning behind the pin, announcing this was the day he was kicking off a campaign to combat antisemitism. Kraft, who invested more than $100 million in the initiative, said “fighting this hate will be the most meaningful and fulfilling action of my life.”

He was leading with his heart, which is also what he has said led him to first hire Belichick in 2000 — a decision that wasn’t universally viewed as shrewd until the Lombardi Trophy made its way to Foxborough in Belichick’s second season.

Kraft sometimes compared the dynamic among himself, Belichick and quarterback Tom Brady to “a marriage because you put up and go through a number of things that the general public probably can’t appreciate.”

He took great pride in keeping the trio together for 20 years. Brady’s departure as a free agent in 2020 pained him. And now comes another ending, this one with Belichick.

In the championship years, it was seldom considered how Belichick’s outside-the-box actions — such as what he did with the blue square pin — reflected his relationship with Kraft. But as the losses started to pile up in recent years, every interaction, team decision and news release was scrutinized through that lens.

After helping the Patriots win six Super Bowls, Belichick’s team finished this season 4-13. It was the third losing season in four years.

One team source who witnessed interactions between Belichick and Kraft said: “I don’t know what happened to that relationship, but it doesn’t seem to be in as great of a place as it used to be.”

On Thursday, the Patriots announced that Kraft and Belichick agreed to part ways. At the news conference, they shared an embrace, each thanking the other, putting a happy face on their final chapter together.

PERHAPS THE MOST seismic shift for the Kraft-Belichick pairing came on March 16, 2020 — the day Brady drove to Kraft’s home in Brookline, Massachusetts, to tearfully tell him he was leaving the Patriots.

Two months earlier, Kraft told NBC’s Peter King his “hope and prayer” was Brady, whom he viewed like a son, would play for the Patriots or retire. The Hail Mary for Kraft was that Belichick might somehow make it happen.

In fairness to Belichick, there was no historical precedent that a two-year, $50 million free agent investment in a 42-year-old quarterback (which is what the Tampa Bay Buccaneers gave Brady) was a sound business decision.

With Belichick showing no signs of retiring, and Brady committed to keep playing, it put Kraft in a pickle. He hoped Belichick and Brady would have come together over the course of the 2019 season and perhaps realize they were at their best together. Instead, Kraft ultimately had to pick one.

Paying respect to Belichick’s championship résumé and role in raising the Patriots to prominence, Kraft essentially chose him — which meant letting Brady enter free agency and ultimately sign with the Buccaneers.

For Belichick, the selection of quarterback Jimmy Garoppolo in the second round of the 2014 draft was part of the sound, strategic planning for Brady’s eventual departure. But Brady outlasted that plan. Garoppolo was traded midway through the 2017 season, and a new plan had to be hatched for when Brady would ultimately depart.

Brady went on to win a Super Bowl in his first season in Tampa Bay. Meanwhile, the Patriots are 29-38 over the past four seasons, with their lone playoff appearance ending in a 47-17 blowout loss to the Buffalo Bills in the wild-card round of the 2021 season.

Belichick’s handling of the offensive coaching staff when coordinator Josh McDaniels left to become Raiders head coach ahead of the 2022 season — turning to longtime defensive coach Matt Patricia as the new offensive coordinator — began a downward spiral for 2021 first-round quarterback Mac Jones and the offense.

As a result, the latitude Kraft afforded Belichick has slowly eroded since Brady’s departure, with one notable example coming last offseason when the team announced that top defensive assistant Jerod Mayo was negotiating a contract to remain with the franchise long term.

Multiple sources familiar with Belichick’s thinking relayed that he was uneasy with Kraft empowering Mayo that way — positioning him as the heir apparent and creating a dynamic that potentially undercut Belichick’s authority and team culture.

Team sources described the relationship between Belichick and Mayo — a 2008 first-round pick of the franchise, whom Belichick had recruited to the coaching staff in 2019 — as more distant this season than it had previously been.

FOUR DAYS BEFORE the Patriots’ 2023 regular-season opener against the Philadelphia Eagles, something different was unfolding in the middle of the team’s practice field.

Players were loosening up as music blared and Belichick — dressed in black shorts, a blue shirt and a white hat — twirled his whistle as he briskly walked down the middle of the field. Keeping pace to his left was Kraft, dressed in black pants, a long-sleeved light-blue dress shirt and black Nike shoes.

Seeing the 82-year-old Kraft at practice was nothing new; he regularly watches from the sideline and describes himself as the fan who fell in love with the team in the 1960s attending games during the franchise’s AFL days in Boston and as a season-ticket holder in the 1970s.

But the sight of Kraft and Belichick walking the middle of the field together stood out to longtime observers, and even Kraft himself.

“Your favorite coach asked me to come out. He was trying to show me something. I don’t usually go out [on the field],” Kraft explained later that night at a ribbon-cutting ceremony for a $250 million stadium renovation project.

Video of the two splashed across social media and on local newscasts, projecting the image of a unified front, which might have been Belichick’s intention.

At the same time, Kraft was direct when he told reporters later that day: “In the end, we want to win.”

That message had been resonating for months, beginning Jan. 9, 2023, the day after the 2022 season ended in a 35-23 loss to the Bills in Orchard Park, New York. The Patriots, who finished 8-9 with Patricia assigned by Belichick to build an offense and call plays, would have clinched a playoff bid with a win.

Kraft and his son, Jonathan, the team president, quickly delivered a letter to season-ticket members that read in part: “Our expectation was to perform better throughout the season and to advance through the playoffs. We can assure you that no one in our organization is satisfied with the results from this past season. In the weeks ahead, we will be making critical evaluations of all elements of our football operation as we strive to improve and return to the playoffs next year.”

Four days later, the club issued a news release that read: “The New England Patriots and Head Coach Bill Belichick have begun contract extension discussions with Jerod Mayo that would keep him with the team long-term. In addition, the team will begin interviewing for offensive coordinator candidates beginning next week.”

For a team that is notoriously tight-lipped, the news release came across as wildly out of character.

A few weeks later, the team announced the hiring of offensive coordinator Bill O’Brien, who had served in that role in 2011.

Sources familiar with Belichick’s thinking relayed that he believed the Patricia-led offense had been making strides, so while he was willing to go along with a new hire and has since lauded O’Brien as a coach, he wasn’t the primary driver of the switch.

Similar to what unfolded with Mayo, sources familiar with Belichick’s thinking relayed that he viewed it as another example of increasing involvement from Kraft.

WHENEVER PATRIOTS PLAYERS return to the locker room after a victory, they can almost always count on Kraft as one of the first to greet them.

So it stood out to one player after a thrilling 21-18 road win over the Steelers on Dec. 7 that Kraft was not there in Pittsburgh. Kraft hadn’t attended the Thursday night game.

The next night in Boston, at the gala ahead of the Army-Navy game at Gillette Stadium, Kraft told WBZ-TV how he was finally able to “feel good” and sleep — a reflection of the toll the season had taken on him.

Players also took note that Kraft was not in Denver when the Patriots posted an exciting 26-23 victory over the Denver Broncos on Christmas Eve. Some with longtime ties to the franchise noted that it was unusual for Kraft to miss a road game, but to longtime Patriots media members, two in a row seemed unprecedented, sparking speculation that perhaps he was sending a subtle message to the tunnel-visioned Belichick.

In arguably the most trying season in Kraft’s 30 years of ownership, some close to him believed he was most upset after the team’s 10-6 loss to the Indianapolis Colts in Frankfurt, Germany, on Nov. 12. The franchise had invested millions as part of their international initiative leading into the game, spanning a calendar year, and the team’s lackluster performance was disheartening to him.

Leading into the game, he told NFL Network about the season to that point: “It’s really disappointing. This isn’t what we were expecting to happen this year.”

Kraft attended the team’s final road game Dec. 31 in Orchard Park, New York — as well as the home finale against the Jets, wearing a blue hoodie while watching from the owners box — walking the sideline at Highmark Stadium before kickoff and stopping at the Patriots’ bench where he briefly spoke with O’Brien. Jonathan Kraft was also on the sideline and at one point had a quick chat with Mayo before they watched the game from a suite.

What unfolded in the 27-21 loss looked familiar to most of the regular season — major offensive struggles. The Patriots had four turnovers in the first 18 minutes, the defense fought valiantly to keep the team in the game, but they ultimately came up short.

With the result decided at the two-minute warning, the Krafts rode an elevator to the tunnel, not far from both teams’ locker rooms. They turned left and walked up a ramp to the outside, leaving behind a defeated team and one major question to answer:

Would they bring back Belichick for a 25th season in 2024 or take back full control of the franchise?

Their actions two weeks later provided the decisive answer.