The Dallas Cowboys defense was a top-5 unit last season, leading the league in takeaways and ranking second in points allowed. This year, they have fallen to the middle of the pack. What went wrong?

The most significant change was personnel. The Cowboys lost several key contributors in free agency, including a starting cornerback and their top pass-rushing linebacker. These departures have forced the team to rely on younger, less experienced players.

But personnel is only part of the story. Defensive coordinator Dan Quinn made several schematic adjustments that have not worked as planned. The team has played more zone coverage this season, moving away from the aggressive man schemes that defined their success.

The zone coverage has been particularly vulnerable against quick passing attacks. Teams are completing 72% of passes against Dallas zone coverage, compared to 58% against their man looks. The problem is that the Cowboys no longer have the cornerbacks to play man consistently.

Another issue is the pass rush. Without the same caliber of edge rushers, Dallas is generating pressure on only 28% of dropbacks, down from 35% last year. This gives quarterbacks more time to find open receivers.

The Cowboys have tried to compensate by blitzing more frequently. They are sending extra rushers on 34% of plays, up from 26% last season. But without the coverage talent to hold up on the back end, these blitzes are being exploited.

There is no easy fix for Dallas. They need to develop their young players and may need to make significant additions in the offseason. Until then, this defense will continue to struggle against quality opponents.