After the big kahuna hit over the weekend with Jon Gruden officially going to the Raiders, one of the next head-coaching dominos fell. It is going to involve Andy Reid's coaching tree adding another branch, as Chiefs offensive coordinator Matt Nagy was hired by the Bears, the team announced Monday.

Adam Jahns of the Chicago Sun-Times first reported the news.

The decision by GM Ryan Pace, himself just 40 years old, to hire a youthful offensive coordinator -- Nagy is just 39 years old -- as head coach follows a couple of trends and makes some logical sense in terms of trying to develop Mitchell Trubisky

Nagy is one of several former Delaware quarterbacks to find success in the NFL. He joins Joe Flacco and Rich Gannon as famous Blue Hens to make it big, although the other two obviously hit it large as quarterbacks in the NFL. Nagy spent time in the Arena Football League before getting into coaching, joining the Philadelphia Eagles as in intern in 2008. He would rise to offensive quality control coach by the 2012 season and then join Reid in Kansas City when Reid was dismissed by the Eagles and hired by the Chiefs that offseason.

Reid brought Nagy in as his quarterbacks coach when he made the leap to KC and Nagy, along with Brad Childress, would replace Doug Pederson as co-offensive coordinators in 2016. He took over as OC in 2017 and would take over playcalling duties (Reid stripped himself of that) midway through the 2017 season and helped engineer a rejuvenation of the Chiefs offense. 

Kansas City would eventually win the AFC West thanks to its explosive second-half offense, although things did not end well for the Chiefs, who blew a 21-3 halftime lead against the Titans during Wild Card Weekend (more on that in a second). Chiefs fans can blame the referee situation -- that certainly was a problem -- and missing Travis Kelce in the second half was also a big issue. But there will be questions about the offense and Bears fans will at least be pondering what happened in the second half.

Regardless, Reid has called Nagy one of the best head-coaching prospects he's ever had underneath him as an assistant. That's stout praise for the guy who helped to mentor a lot of future head coaches (more on that too): Pederson, John Harbaugh, Ron Rivera and Sean McDermott, just to name a few.

Young Offensive Guys

When the Rams hired Sean McVay last year, there were some concerns about how he would handle the gig. But then the Rams won 11 games and there were no more questions, just fawning over the job McVay did in the role and the development of Jared Goff at quarterback. Clearly the Bears wanted to follow the same formula and create the Rams 2.0, and now you're seeing it from Pace, who decided to hire a 39-year-old. 

Out with old defensive dude Jeff Fisher in L.A., in with the young stud OC McVay. Out with the old defensive dude in Chicago, in with the young stud OC Nagy. 

There's a reasonable comparison to be made, too, with Jordan Howard serving as a poor man's Todd Gurley and a team that needs to go out and get some wide receivers. The offensive line is impressive and, just like Travis Kelce before him, Adam Shaheen has been referred to as a "Baby Gronk." 

Expecting the Bears to make a massive leap into the 11-win range next year is probably asking a lot, but if they make big offensive strides, there will be lots of happy people in Chicago.

Developing Trubisky

Of course, it all hinges on what to do with Trubisky, the second-overall pick in the 2017 NFL Draft. Goff was No. 1 in 2016 and looked horrible during his rookie season but broke out in a big way this year and flashed throughout the season. Trubisky wasn't terrible this season, but he had no one to throw to -- Dontrelle Inman was acquired by Chicago midseason and went from being the fifth option for the Chargers to the Bears' top receiver. That's a problem.

Trubisky hasn't spent a ton of time under center -- he largely played out of the shotgun at North Carolina -- and spent most of his rookie season rolling out and running some sort of modified Shanaclan system on offense that stressed bootlegs and utilized his speed. He has impressive accuracy, though, and lit up the preseason last year. 

If Nagy can incorporate some of the spread principles with a West Coast attack, which is what Reid installed with the Chiefs, and utilize a lot of run-pass-option stuff, the same way Pederson did with the Eagles, it's not hard to imagine Trubisky having a really nice "leap forward" type of sophomore season. 

Everything about Nagy's first year will hinge on how Trubisky looks.

Keeping Fangio?

If the Bears want to compete, the defense needs to not stink. The defense outplayed expectations in 2017, finishing 14th in Football Outsiders DVOA rankings. A large part of that comes with Vic Fangio doing a tremendous job of scheming up the defense, because the personnel isn't there to just be great regardless of who runs the defense. 

The problem is, Fangio did a really good job. Which means he could be bolting.

Chicago has roughly 12 hours to figure something out before Fangio is a free agent.

Don't be surprised to see them make a full-court press here, but it's anybody's guess whether he will click with Nagy or not. Having some consistency on that side of the ball would go a long way toward helping out Nagy's first year.

Questions about that playoff game

There's no way for Nagy to get a head-coaching gig without someone asking him about the job the Chiefs did in the second half of the playoff game Saturday. It stands to reason that he was already the guy for Chicago -- good job again by Pace on keeping things quiet on that front, just like he did with Trubisky -- because of the timing here. Unless they hammered out an agreement on Sunday in the wake of the loss anyway. 

The Chiefs were leading 21-3 at halftime. The game should have been over against a Titans team that wasn't built to storm back, due to the reliance on the running game. The Chiefs scored ZERO POINTS IN THE SECOND HALF. ZERO.

Kelce was missing, but it still begs questions about what happened and how Kareem Hunt could finish the game with 11 touches when the Chiefs had that kind of lead. Maybe you peg it on Reid, but, man, that is not a great first point to make when it comes to talking about the Bears new hire.

Andy Reid coaching tree

So now that Nagy's been hired, Reid has a ridiculous amount of former coaches in the NFL. There are seven -- that's more than 20 percent! -- head coaches in the NFL who previously worked for Reid.

Or Reid himself: he obviously counts as a member of his tree, working in Kansas City. John Harbaugh in Baltimore, Ron Rivera in Carolina, Doug Pederson in Philadelphia, Todd Bowles with the Jets, Sean McDermott in Buffalo and now Nagy in Kansas City.

If Pat Shurmur of the Vikings gets hired that will be 25 percent (!!!) of NFL coaches who come from the Reid tree. A large number of those are either defense or special teams; Pederson, Nagy and Shurmur (along with Reid) are the only guys who do offense, so it's not like the spread/West Coast attack will take over football.

But don't be surprised to see the continued proliferation of it thanks in large part to Reid growing his roots.