Close friends of Bill Belichick seem to think that the Patriots coach, in his 18th season in Foxborough, is going to call it quits soon.

In a story from ESPN: The Magazine about how much longer Tom Brady might play, the longevity of Belichick also came up, and it sounds like the Patriots coach might soon be ready to put the NFL grind behind him.

According to the story, Belichick's friends believe that he'll only coach for two or three more years, which would keep him on the Patriots sideline until 2019 or '20. Although the thought of Belichick retiring might sound crazy, the truth is, there's not a lot left for him to accomplish.

At 65, Belichick already has the most playoff wins in NFL history, the most Super Bowl wins by any coach and he even has a perfect regular-season under his belt. The only thing left that Belichick could possibly even think about doing is becoming the NFL's all-time winningest coach. However, it would probably take at least five more seasons of coaching for Belichick to top Don Shula's all-time record of 347 wins (including playoffs).

Through eight weeks this season, Belichick has 269 career victories, which means he would need 78 to tie Shula. With that goal probably out of reach, it seems that Belichick has decided to spend the next few years making sure the "Patriot Way" remains in place after he retires.

According to the ESPN story, friends believe that Belichick wants to stick around long enough "to ensure that his two sons, Stephen and Brian, both Patriots assistants, are secure, and possibly long enough to establish a truly dynastic succession."

The end is near enough that Belichick apparently gave a potential retirement date to Patriots owner Robert Kraft before Super Bowl LI.

"As long as he wants," Kraft said when asked in February how long Belichick might coach. "We have a pact that we don't talk about that. He knows and I know. But he won't be done this year."

Belichick was asked about retirement during a CNBC interview in April and he didn't exactly sound like a guy who plans on coaching forever.

"Again, I'm kind of shortsighted here," Belichick said at the time. "I'm good. Certainly good here this year. Good for a while. I like what I'm doing. I enjoy all parts of the game -- the team building, training camp, game days, the excitement of Sunday."

Before Brady turned bionic, there was a thought -- even noted in the ESPN story -- that Belichick might want to try and win a Super Bowl without Brady. However, the Patriots quarterback has made it clear he's not going to retire anytime soon, and based on his stats from this season, it doesn't look like his play is going to fall off anytime soon, either.

By trading Jimmy Garoppolo, it seems Belichick has finally bought into the notion that Brady might actually be able to play until he's 45.

The fitting way for this to end would be for Belichick and Brady to ride off into the sunset together after the 2020 season. At that point, Brady would be 43 and it would give the pair a chance to add to their Super Bowl trophy haul that will be almost impossible for any coach or quarterback to match for the rest of time.