FOXBOROUGH, Mass. (AP) — Six-time NFL champion Bill Belichick agreed to part ways as the coach of the New England Patriots on Thursday, bringing an end to his 24-year tenure as the architect of the most decorated dynasty of the league’s Super Bowl era, a person with knowledge of the situation told The Associated Press on the condition of anonymity because it has not yet been announced.

ESPN first reported the decision. A news conference is planned for later in the day in which team owner Robert Kraft and Belichick will address the decision.

Belichick, 71, became just the third coach in NFL history to reach 300 career regular-season wins earlier this season, joining Hall of Famers Don Shula and George Halas. With 333 wins including the playoffs, Belichick trails only Shula (347 wins) for the record for victories by a coach.

But the Patriots ended this season 4-13, Belichick’s worst record in 29 seasons as an NFL head coach. It supplanted the 5-11 mark he managed in his last year in Cleveland in 1995 and again in his first year in New England in 2000. Including the playoffs, he ends his Patriots tenure with a 333-178 overall record.

With his cutoff hoodies and ever-present scowl, Belichick teamed with quarterback Tom Brady to lead the Patriots to six Super Bowl victories, nine AFC titles and 17 division championships in 19 years. During a less successful — but also tumultuous — stint with the original Cleveland Browns, Belichick earned 37 of his career victories.

It’s not immediately clear who Kraft will tap to replace the future Hall of Famer.

Patriots linebackers coach Jerod Mayo won a Super Bowl ring playing under Belichick and has interviewed for multiple head coaching vacancies since becoming a New England assistant in 2019. Mayo turned down a few interviews last offseason before signing a contract extension to remain with the Patriots.

Mike Vrabel, who was fired earlier this week by the Tennessee Titans and won three Super Bowls with the Patriots, is also expected to be a candidate for the head coaching job.

Belichick had been grooming offensive coordinator Josh McDaniels to replace him before McDaniels left following the 2021 season to become the coach of the Raiders. He has since been fired by Las Vegas. Belichick’s two sons, Steve and Brian, are also on the coaching staff.

Belichick’s exit from the Patriots comes just a day after another legendary coach and his longtime friend Nick Saban announced he’d retire after winning seven national championships at the collegiate level. Saban worked for Belichick’s father, Steve, in the 1980s as a coach at Navy. Bill Belichick went on to hire Saban as his defensive coordinator when he became Cleveland’s head coach in 1991.

The six Super Bowl wins tie Belichick with pre-merger mentors Halas and Curly Lambeau for the most NFL championships. Belichick also won two rings as Bill Parcells’ defensive coordinator with the New York Giants.

But the Patriots have stumbled to a 29-38 record since Brady departed following the 2019 season and missed the playoffs in three of those four seasons. Beginning in 2001 when Brady became the starting quarterback, the Patriots missed the playoffs only once (2008) when Brady was injured. This marked New England’s fifth consecutive season without a playoff victory.

Belichick’s subsequent solutions at quarterback haven’t panned out.

Brady’s initial replacement, Cam Newton, didn’t resemble the player who won the 2015 MVP award and was cut after a 7-9 finish in 2020. Meanwhile Brady won his seventh Super Bowl ring with the Tampa Bay Buccaneers that same season.

Potential long-term replacement Mac Jones, a 2021 first-round draft choice, was a Pro Bowl selection as a rookie and led New England to the playoffs. But he regressed in Year 2 when Belichick put longtime defensive assistant Matt Patricia in charge of the offense. Jones didn’t fare much better this season when Bill O’Brien returned as offensive coordinator. He was benched four times before being replaced as starter by backup Bailey Zappe for the final six games.

That left the Patriots looking at a lengthy rebuild, with no candidate on the roster to bring stability to the sport’s most important position.

Belichick, who also served as the de facto general manager with final say on personnel decisions, was celebrated for his ingenuity managing the salary cap during the run of Super Bowl success. It included getting stars like Brady and others to accept cap-friendly contracts or adjust their deals to accommodate the signing of other players.

But that acclaim has waned in the years since Brady left, as a run of draft picks and high-priced free agents didn’t live up to expectations. In addition, Belichick has seen several members of his personnel and scouting departments leave for other jobs. The list includes his former player personnel director, Nick Caserio, who was hired as Houston’s general manager in 2021.

Now it won’t be Belichick making the decisions for the Patriots on or off the field.

The only child of a World War II veteran who spent three decades as a Navy assistant coach, Belichick is a football historian with an encyclopedic knowledge of strategy from the sport’s early days to current NFL trends. His players said his attention to detail never left them unprepared.

Belichick has been a master of the NFL rule book, unearthing loopholes in clock operations and offensive line formations that — though entirely legal — cemented his reputation as a mad genius.

But his legacy in New England also includes two major cheating investigations — and other, minor ones — that cost him and the team draft picks and more than $1 million in fines. Opponents accused the Patriots of everything from hacking their headsets to cutting corners on injury reports.

His friendship with former President Donald Trump, which Belichick insisted was not political, landed the coach on the list to receive a Presidential Medal of Freedom in the waning days of the administration. After the outcry against the U.S. Capitol siege, Belichick announced “the decision has been made not to move forward.”