Entering the third year of the Chip Kelly era, the Eagles are at something of a crossroads. Yes, the team has won 20 games over the last two years, and won the NFC East in Kelly’s first year. But that was then. In many ways, the highlights of Kelly’s first game as head coach, the Monday night thrashing in Washington, seem almost like they came from another team, replaced by All Pro players like DeMarco Murray, and some, like Evan Mathis, not replaced at all.

But all of those moves are secondary to the one that may well ultimately define Kelly’s tenure in Philadelphia. Yes, more than trading the franchise’s all-time leading rusher. And yes, more than wresting control of the front office.

It’s the quarterback, stupid.

During the offseason Kelly traded incumbent starting quarterback Nick Foles and a second-round pick to the Rams in exchange for Sam Bradford, a quarterback with some elite-level tools and the dreaded label of "bust". Now, Kelly and the Eagles will try to take the next step with a quarterback who hasn’t played a full season since 2012. If Kelly’s style of team building hadn’t been considered unorthodox before, it certainly is now.

Bradford was supposed to be the franchise quarterback to lead the Rams out of the mire of mediocrity. Instead, he finished his five-year tenure in St. Louis with a record of 18-30-1, a 58.6 completion percentage and two consecutive ACL injuries. Bradford is still rehabbing his latest knee injury with the hopes of returning to the practice field by the start of training camp. If he can, he’ll be placed into a system that many observers have called "quarterback-proof".

But even if he is able to play come preseason, no one seems quite sure what to expect. He’s a quarterback with a good-to-great arm and above-average accuracy, even if his stats don’t necessarily show it. But is he better than Foles or Mark Sanchez, who finished last season as the starter in Philadelphia? And is it too late, in his sixth pro season, to fulfill the potential that got him drafted first overall?

Bradford finished his time in St. Louis with 11,065 passing yards, 59 touchdowns and 38 interceptions. Since 2000, 16 quarterbacks – Bradford included – have posted similar (or superior) stats in their first four seasons. Of those, four are entering their fifth seasons in 2015. As for the remaining 11, their fifth seasons provide some insight into what the Eagles might expect to see out of Bradford in 2015.

(It’s important to note here that Bradford missed the entire 2014 season with an ACL injury, and thus his numbers are being compared against players entering their fifth seasons.)

Name Year Team Games Started Att Comp Comp % Yards TDs INTs QB Rate Josh Freeman 2013 2 Teams 4 4 147 63 42.9 761 2 4 52.6 Mark Sanchez 2013 Injured Matt Stafford 2013 DET 16 16 634 371 58.5 4650 29 19 84.2 Joe Flacco 2012 BAL 16 16 531 317 59.7 3817 22 10 87.7 Matt Ryan 2012 ATL 16 16 615 422 68.6 4719 32 14 99.1 Jay Cutler 2010 CHI 15 15 432 261 60.4 3274 23 16 86.3 Eli Manning 2008 NYG 16 16 479 289 60.3 3238 21 10 86.4 Carson Palmer 2008 CIN 4 4 129 75 58.1 731 3 4 69.0 Ben Roethlisberger 2008 PIT 16 16 281 469 59.9 3301 17 15 80.1 Marc Bulger 2006 STL 16 16 588 370 62.9 4301 24 8 92.9 Aaron Brooks 2004 NO 16 16 542 309 57.0 3810 21 16 79.5





Of the seven quarterbacks on this list who finished all 16 games in their fifth year, the results are mostly positive: the median stat sheet comes out to 317-of-542 for 3,817 yards, 22 touchdowns and 14 interceptions. That’s an 86.4 quarterback rating.





For context, 86.4 is the exact quarterback rating 49ers quarterback Colin Kaepernick posted last season, which ranked 20th among all quarterbacks last year. Meanwhile, 3,817 yards would have been good for 13th among all quarterbacks last season. Add to that the fact that no Eagles quarterback has thrown for more than 3,000 yards since Michael Vick in 2011, and it would appear that all signs point to a best-case scenario of a top-15 ceiling for Bradford in 2015.





But obviously, projections don’t tell the whole story. The injury question still lingers, and the touchdown numbers seem small for a Chip Kelly offense. Then again, the Eagles’ running backs are expected to be the focal point of the offense, so a league-average performance by the quarterback could end up being more of a boon that it may be on another team.

And that’s to say nothing of the Chip Kelly Effect. Consider that, with all the turmoil behind center last season, both Eagles starting quarterbacks threw for a combined 27 touchdowns. And in 2013, Foles threw for him famous 27 touchdowns, with Vick adding five more. So in two injury-filled and inconsistent seasons of quarterbacking, no Kelly-led Eagles team has accrued fewer than 27 passing touchdowns in a season.





Passing yards follows a similar pattern. Though three quarterbacks have played in meaningful games over the last two years, the team has finished with over 4500 passing yards each of the last two seasons (4907 in 2013, 4595 in 2014). Interceptions, meanwhile, have been about the same under Kelly as they appear in the projections: Eagles quarterbacks threw eight in 2013 and 21 last year.





So where does an extra 700 yards and five touchdowns put Bradford on the list of last year’s quarterbacks? Well, 4,500 yards would put knock Eli Manning out of sixth place, while 27 touchdowns ties Ryan Tannehill and Joe Flacco for 12th.





All of this is to say that a healthy Bradford’s baseline in any normal offense would be a league-average quarterback, but being in Philadelphia could potentially elevate him into the top 10-to-12 range.









According to those projections, the Eagles will run the ball 418 times, which is likely a low figure. Over the last two seasons the Eagles have run the ball 500 and 474 times, respectively. This is in line with the average of 1091 offensive plays run per season: 542 projected pass attempts and 500 rushes paints a more accurate picture.





As with all projections of this kind, it’s a leap of faith to assume Kelly and Bradford will have this kind of success together. But the numbers do paint an intriguing picture of the kind of quarterback Kelly has received from St. Louis. And if Bradford is able to stay healthy, all signs point to Kelly being able to maximize his talent.



