Bill Belichick's coaching tree has had many branches over the years, as his assistants have often been among the most sought-after coaching candidates in the league.
However, in recent years, the tree has expanded in a different way: Belichick's former players are now joining the coaching ranks, and a few have landed prominent NFL gigs.
That includes Cardinals coach Kliff Kingsbury.
Kingsbury was one of Belichick's earliest quarterback draft picks with the Patriots. He was selected with the 201st pick in the 2003 NFL Draft, and the team planned on developing him behind Tom Brady.
Kingsbury's NFL playing career didn't quite work out, but his time with the Patriots helped shape him into the coach that he is today. Here's what to know about his stint in New England along with his relationships with both Belichick and Tom Brady.
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Kliff Kingsbury with the Patriots, Tom Brady, Bill Belichick
Kingsbury spent one season with the Patriots after being selected in the 2003 NFL Draft. He felt like he was able to get a lot out of his time with Belichick despite being with the team for just a short time.
"I think it was such an eye-opener what all he has put into this game and to do it at that level for that long," Kingsbury explained of Belichick's impact on his career ahead of Week 14, per Patriots.com. "I'd been around some great coaches. My dad was a high school coach, but just to watch the processes they had in New England from kind of behind the veil was incredible.
It was a crash course in football, and I learned more in the time there than the rest of my life put together probably. It's a Football 101 for anybody who's been through that program — coaches, players, anybody. To see him still doing it and the level he's doing it at is just incredible.
That proved valuable to Kingsbury. He had initially planned on carving out a long career as an NFL quarterback, but when that didn't pan out, he turned to coaching as a fallback.
He believes he was well-prepared for that path thanks to his time with the Patriots.
"At the time, I didn't realize what a blessing it would be moving forward going into coaching and things of that nature," Kingsbury told ESPN in 2020. "You really get your Ph.D up there when you're involved in the coaching side of it all."
Beyond that, Kingsbury also explained that he learned he wouldn't quite be the next Tom Brady while with the Patriots. Though it was early in Brady's career, Kingsbury quickly identified that there was something different about his teammate.
"Every part of his life was dedicated to being the best quarterback in the history of the game," Kingsbury said, per ESPN. "He already knew it then where it was heading. It was insane."
Still, Kingsbury learned about quarterback play from Brady and the two have remained friends in the years since Kingsbury's departure from New England.
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Kliff Kingsbury NFL teams
Kingsbury was a journeyman of sorts during his brief NFL playing career. He was never in any stop for more than one season, and that included his time with the Patriots.
Kingsbury spent the 2003 season with the team that drafted him, but he was on IR with an arm injury. The Patriots released him ahead of the 2004 NFL season and from there, he bounced to four NFL teams over a three-year span.
By the end of Kingsbury's playing career, he was a member of the Winnipeg Blue Bombers in the CFL. He eventually retired following the 2007 season and last was on an NFL roster in 2006 with the Bills.
Below is a look at Kingsbury's year-by-year career as an NFL player.
| Team | Years |
| Patriots | 2003-04 |
| Saints | 2004-05 |
| Broncos | 2005 |
| Jets | 2005 |
| Bills | 2006 |
Kliff Kingsbury stats with Patriots, other teams
Kingsbury got into just one regular-season game during his NFL career, in 2005. It came in a 27-0 Jets loss against the Broncos during which New York starter Vinny Testaverde struggled mightily.
In that contest, Kingsbury completed 1 of 2 passes for 17 yards. That marked the entirety of his stat line outside of the NFL preseason.
Kingsbury did play in the NFL Europe during the 2006 offseason. The Jets assigned him to the Cologne Centurions and in that action, he completed 58 of 102 passes for 633 yards, two touchdowns and two interceptions. His passer rating of 73.7 ranked fifth among the seven quarterbacks to attempt 100-plus passes during that season.
Kliff Kingsbury coaching record, stats
Kingsbury, 43, became a top NFL coaching candidate in 2019 because of his innovative offensive system and the recent success of other young, offensive-minded coaches across the league. That's why the Cardinals hired him despite the fact that he had been fired by Texas Tech after six years in charge of that program.
The results have been mixed for Kingsbury. He guided the Cardinals to a playoff berth in 2021 after a 7-0 start, but his tenure has largely been defined by early-season success and late-year collapses.
Kingsbury has a total record of 28-32-1 entering Week 14 of the 2022 NFL season. Below is a look at his record by season as well as his offensive and defensive ranks by season.
| Season | Record | Yards/game | Points | Yards allowed | Points allowed |
| 2019 | 5-10-1 | 21st | 16th | 32nd | 28th |
| 2020 | 8-8 | 6th | 13th | 13th | 12th |
| 2021 | 11-6 | 8th | 11th | 11th | 11th |
| 2022 | 4-8 | 20th | 17th | 21st | Last |
The Cardinals made the playoffs following the 2021 NFL season but lost in the wild-card round to the eventual Super Bowl champion Rams. Arizona was blown out in that game 34-11, and that gave Kingsbury an 0-1 career playoff record.
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Quarterbacks drafted by Bill Belichick
Belichick has made a habit of drafting quarterbacks during his 23-year run with the Patriots. The team has selected a total of 14 players at the position since 2000, the first of whom was Tom Brady and the most recent of whom is rookie Bailey Zappe.
Below is a look at the quarterbacks Belichick has selected during his time in New England:
| Year | Player | Round | Pick |
| 2000 | Tom Brady | 6 | 199 |
| 2002 | Rohan Davey | 4 | 117 |
| 2003 | Kliff Kingsbury | 6 | 201 |
| 2005 | Matt Cassel | 7 | 230 |
| 2008 | Kevin O'Connell | 3 | 94 |
| 2009 | Julian Edelman | 7 | 232 |
| 2010 | Zac Robinson | 7 | 250 |
| 2011 | Ryan Mallett | 3 | 74 |
| 2014 | Jimmy Garoppolo | 2 | 62 |
| 2016 | Jacoby Brissett | 3 | 91 |
| 2018 | Danny Etling | 7 | 219 |
| 2019 | Jarrett Stidham | 4 | 133 |
| 2021 | Mac Jones | 1 | 15 |
| 2022 | Bailey Zappe | 4 | 137 |
