Player trades aren't as common in the NFL as they are in baseball or some other sports, but the Philadelphia Eagles do seem to be a rare exception. As Zach Berman pointed out in this New York Times story from a week and a half ago, since Howie Roseman became GM 27 months ago the Eagles have made more trades involving players (i.e., not just draft picks) than any other team in the league. (They were tied with Seattle at 15 at the time the story was published, and they traded Asante Samuel a few days later).
Now, on the topic of how the Eagles do with these trades, we turn to Sheil Kapadia, who has broken down the return the Eagles have received on two recent high-profile deals -- the ones that sent quarterbacks Donovan McNabb and Kevin Kolb out of town.
As Sheil shows, the picks the Eagles got back from McNabb have netted them safety Nate Allen and linebackers DeMeco Ryans and Casey Matthews. That's two projected 2012 defensive starters and a guy, in Matthews, who will get at least some playing time. Not a bad haul for a player it's now clear was basically done at the time of the deal. Yes, McNabb did beat the Eagles once while with the Redskins in 2010, but he hasn't made a significant contribution since he left Philadelphia.
The Kolb trade brought back cornerback Dominique Rodgers-Cromartie, and the picks that produced defensive end Vinny Curry and cornerback Brandon Boykin. Rogers-Cromartie is projected to be a starting cornerback for the 2012 Eagles. Boykin could be the nickel corner and a factor in the return game. Curry is likely to factor into the pass-rush rotation. Not a bad return for a quarterback who would have been their backup in 2011 had they kept him.
When you watch the Eagles' defense in 2012, you should get some idea why it's so important to Andy Reid to be deep at the quarterback position. This is why he drafted Nick Foles this year -- in the hopes that he eventually gets something out of him, whether it's actual playing time for the Eagles or something of value in trade. It's about more than just having good backup options behind starter Michael Vick. It's about how much quarterbacks are worth in today's NFL. By trading two of them over the past three offseasons, the Eagles have helped build their 2012 defense.