In the near future, the Eagles will find themselves at a crossroads that they have not been at in for quite some time. With Andy Reid soon to be jettisoned from the Eagles' head coaching job, the Eagles organization will have a huge decision to make. The new head coach will build his new team based on the NFL philosophy he thinks will work best. But who is that coach, and what will that philosophy be? Of course, these aren't questions we don't have the answer to yet. A closer look at two main NFL philosophies may reveal who should be the new coach and what should be his philosophy, however.

I'm a believer that there are two general NFL philosophies on how to style and build a successful NFL team. Within these two general categories are multiple subdvisions, and some exist that may even incorporate both theories.

These are the two general models I believe in:

Model 1) The Team With A Very Good QB

and

Model 2) The Team Without A Very Good QB

(The naming system isn't pretty, I know.)

Model 1

The focal point of this model is obviously the very good (or even elite) QB. Having a very good QB is worth a lot in the NFL today. Why? Simply put: this type of QB can carry a team to wins. As the cliche goes: it's a passing league.For example, look at this graph from 2011 (h/t JimmyK):

via blogs.mcall.com

Those are the bottom 6 defenses (in terms of yards allowed) in the NFL from 2011. Two of those teams played in the Super Bowl (Giants, Patriots). Another one went 15-1 in the regular season (Packers). "How can a team have such a bad defense and still be so succesful?" one might ask. It's simple: very good QBing. Having a very good QB negates those terrible defenses because the QB can single handidly carry his team to wins.

Now this isn't to say you shouldn't try to have a good defense too. Of course you should try to make your team the best it can be in all phases. Having a good defense will certainly help the team win. But with a salary cap and limited resources it's hard not to prioritize certain positions. In this model, the QB is highly prioritized along with his accommodating pieces on offense: OL, WR, RB, good OC, etc.

This model is historically successful. Teams don't regularly win championships without having a very good QB. Let's take a look some past Super Bowl winners starting from the 2001 SB, along with the team's defense. (I use FootballOutsiders' rankings for reference. Numbers represent the rank among the QBs for offense + league for defense, not the actual quantity of the stat.):

2001 - Ravens, Trent Dilfer - 39 DYAR, 39 DVOA ... Defense: 2
2002 - Patriots, Tom Brady - 13 DYAR, 12 DVOA ... Defense: 13
2003 - Bucs, Brad Johnson - 10 DYAR, 11 DVOA ... Defense: 1
2004 - Patriots, Tom Brady - 9 DYAR, 11 DVOA ... Defense: 2
2005 - Patriots, Tom Brady - 4 DYAR, 4 DVOA ... Defense: 8
2006 - Steelers, Big Ben - 7 DYAR, 2 DVOA ... Defense: 4
2007 - Colts, Peyton Manning - 1 DYAR, 1 DVOA ... Defense: 24
2008 - Giants, Eli Manning - 40 DYAR, 34 DVOA ... Defense: 11
2009 - Steelers, Big Ben - 26 DYAR, 27 DVOA ... Defense: 1
2010 - Saints, Drew Brees - 2 DYAR, 3 DVOA ... Defense: 23
2011 - Packers, Aaron Rodgers - 4 DYAR, 4 DVOA ... Defense: 2
2012 - Giants, Eli Manning - 8 DYAR, 9 DVOA - Defense: 22

Now, SB wins aren't the only way to measure effectiveness of this model. The playoffs, just like in most sports except the NBA, are a crapshoot to an extent thanks to the one game elimination format. But look around the NFL and it's obvious the teams with the best QBs are the more successful teams. Current examples are the Packers - Rodgers, Broncos - Manning, Patriots - Brady, etc.

Only 3 of these SB QBs weren't among the top QBs in the league at the time of the SB win. Of those 3, only 1 wasn't a proven franchise QB that was capable of playing at a high level (Dilfer in 2000). 2 of those teams had a top 2 defense to help them win. Clearly, this data shows the QB position is important and a team designed after Model 1 understands that. A great defense certainly helps too, as shown in the data, but it isn't easy to win a championship in spite of having a very good QB. That's the exception to the rule, and it's also known as Model 2.

Before I get into Model 2, allow me to offer a cross-sport analogy: In the NBA, teams don't win championships without having at least one superstar. A team without a superstar is more often than not mediocre at best: look at the Sixers since Allen Iverson left. The exception to this rule is a team like the 2004 Detroit Pistons, but it's exactly that: an exception. The comparison to the NFL is similar except replace "superstar" with "very good QB".

Model 2

Model 2 exists as the exception to the more succesful Model 1. This model lacks a very good QB but features an ELITE defense and a vaunted rushing attack. Some examples of this model were already shown in the SB data above. The 2000 Ravens are a perfect example. They completely lacked a QB but had a top 2 defense and a very, very strong rushing attack (~2200 yards rushing, largely in part due to Jamal Lewis and Priest Holmes). The concern here is that 2000 was a long time ago now and it's a different styled NFL. A more current example is the Chicago Bears who have the 1 DVOA defense but QB Jay Cutler is only 28 in DYAR + DVOA.

Not only is this model less successful, but it's theoretically harder to build. Assembling an elite efense in the league takes finding a number of great defensive players on that side of the ball since there's 11 starters on the unit, not to mention having account for depth. Compared to Model 1 where the focal point is 1 player, the focal point of this model is broader. Having a great defensive coordinator is also important here.

Knowing this, who should the Eagles target?

Tough question. At first, I'm inclined to say the Eagles should target an offensive coach who subscribes to the theory behind the more successful Model 1 and emphasizes the QB position. The problem here is that the Eagles don't have an obvious top QB, unless you really believe in Nick Foles,and they don't have an obvious way to acquire one. Still, I think this is the better model to abide by since it's historically more successful.

But if the Eagles feel they need to "win now" and don't have the patience to find their very good QB, maybe they should take a chance and hire a guy who they think can install an elite defense that can carry the team to wins. Chances are this model won't be successful, but it's still an option.

What will happen?

I'd wager the Eagles hire an offensive guy because they just experienced a lot of success under an offense coach named Andy Reid. There's also been reports that they want another offensive minded guy. I think that's the right way to go because that guy is more inclined towards Model 1.

Your thoughts?

This topic makes for good debate. I've debated with a number on people on BGN/Twitter about this. Obviously, you want to have the best QB and defense as possible. I just don't believe that defenses alone wins championships - but QBs can. My worst fear is the Eagles will fool themselves into thinking that they can win with just a mediocre QB, and that's simply not likely. Kind of like how the Sixers (pre-Bynum) thought they could win a NBA championship without a real superstar. Hopefully I'm wrong.