Who is to blame for the poor performance of the defense?

Clearly, the consensus answer is Juan Castillo, with Andy Reid taking quite a bit of heat as well. I can't definitively refute that, but I'm not sure any fan can. We just don't have enough inside information. All we can do is attempt to interpret what we see on TV and what the numbers say happened.

Going into the season, it became clear that the focus of the defense was going to be the pass. The method of stopping teams from passing would be to change the philosophy of the defensive line to be more aggressive and invest in pass rushers and cornerbacks. While the safety position was addressed with two 2nd round picks in the past 2 years, you generally don't expect first or second year players to be high-level starters (unless they were taken in the 1st round). The linebackers and safeties were clearly an afterthought.

Attempting to assign blame is a massive task that I don't have the patience to address fully. Instead, I'm going to look at how my understanding of the new philosophy compares to what has been happening on the field.

To start, I looked at touchdowns scored on the defense. The Eagles D has allowed 13 TDs in 4 games. 3 were runs, the remaining 10 passes. Bad passing defense, right? Not so fast. Look at who is catching those TDs:

• 1 to a fullback
• 2 to running backs
• 3 to tight ends
• 4 to WRs.

Only 4 of 10 TDs went to WRs and presumably against CBs. Looking at the 4 WR TDs:

1. 2yd completion to Roddy White in the back of the end zone, Kurt Coleman is the nearest defender.
2. 74yd to Victor Cruz. Blitz, so Coleman had the coverage. Makes two bad tackles in a row.
   
3. 28yd to Victor Cruz. Cruz fights for the ball despite tight coverage by Nnamdi Asomugha and Jarrad Page.
4. 30yd to Josh Morgan. Blitz. Closest defender to the catch was Brian Rolle, with Nate Allen and Asante Samuel in the area.

In only one of the four TDs to a WR the Eagles have allowed was a CB the closest defender, and the video shows Cruz made a good catch in double coverage. While it's possible, even likely, that the receiving or rushing TDs could be blamed on a CB in ways I didn't see, it seems pretty clear that generally the CBs haven't been the problem.

But wait, you say, aren't WRs enabling them to drive downfield, gaining lots of yardage? Not really. Only 2 players have gone over 100 yards receiving against the Eagles: Tony Gonzalez (TE) and Victor Cruz (WR), and Cruz had 74 of his 110 come from one play against a safety who apparently forgot how to tackle. Guys like Roddy White, Julio Jones, Hakeem Nicks, and Michael Crabtree averaged 3.25 catches for 36.25 yards and 1 TD to share amongst them. In fact, only 3 WRs have gone over 50 yards receiving in four games.

Between those numbers and the fact that the Eagles are tied for first in sacks, it seems like the defense is working in the areas they focused on. I can't see how you look anywhere but the LBs and S when blame is assigned. I don't know if the problem is the new philosophy, coaching, schemes, playcalling, talent, inexperience, motivation, or unimpressive splash page cartoons. You can certainly blame someone for not addressing those positions in the draft or free agency. You can definitely blame coaching for the 4th quarter collapses.

And yet, whatever the reason, it's hard for me to ignore the evidence indicating that 2 of the 4 (5?) positions and 5 of the 11 players on defense are just not getting it done.