The Offensive Line's struggles have been well documented this season, and while the Panthers pass protection drop off hasn't been nearly as pronounced as that of the run blocking, it certainly has not been superb.
This past Friday, the excellent folks at Football Outsiders published an article detailing coverage sacks, and quarterback/play call sacks by teams this season.
Per the article:
No coverage sack this year has taken place in less than 3.1 seconds, and the vast majority (214 of the 219 coverage sacks) have taken 3.3 seconds or longer. The median time of a coverage sack is 4.1 seconds, so we're talking about sacks where the quarterback had time to check his primary receiver, look at his secondary, eye the back looking for an outlet pass, and then see the rush bearing down on him.
So basically, a coverage sack is when the QB holds the ball for longer than three and a half seconds or so, and is given an appropriate amount of time to make his way through his progression, yet is sacked.
When measuring up coverage sacks for the entire league, the Carolina Panthers fell to 31st in total coverage sacks, giving up 13 coverage sacks, the second most in the NFL. Cam Newton has taken more coverage sacks than almost every single QB in the league (Alex Smith and Colin Kaepernick have combined for 15 coverage sacks; Matt Stafford also has 13 coverage sacks). Those 13 coverage sacks account for 43% of the Panthers 30 sacks; that equates to 3.3% of all passing attempts.
In contrast, the Panthers have only surrendered 1 QB/Play Call sack, which puts them at 8th place in the NFL (0.3% of all passing attempts), in fact, if not for the lack of passing attempts, the Panthers may have ranked first overall (no team has had 0 play call sacks). You can't really blame OC Rob Chudzinski; he's not calling plays that leave Newton out to dry; the protection designs have been sound (in comparison the NY Jets have 10 QB/Play Call sacks, leaving them in last place).
What it boils down to is, Cam Newton is holding onto the ball for too long. The Offensive Line has been subpar this season, but it certainly does not help when the QB is holding onto the ball for longer than necessary.
Now this isn't a total indictment of Cam or his abilities; referring back to the article:
Long sacks usually have a pretty reliable template: a speedy quarterback will decide after a suitable time in the pocket to roll out toward the sideline with an eye on tucking and running, buy some more time, then get picked off by a linebacker or defensive back coming up from coverage before he can get past the line of scrimmage. Or he'll keep running backwards before finally getting run down for a big loss.
Many of Cam's coverage sacks fall under that category, however, there are external factors at play.
The Panthers have not had great play in the WR Corps. Whether it be a lack of separation, or inexperienced play at WR, the Panthers do not have an absolute game breaker at WR. Don't get me wrong, Steve Smith is a legitimate #1 WR, however, he's reaching the twilight of his career, and has been afforded a lot of attention from opposing teams.
These sacks have killed Panthers' Drives, and stalled offensive momentum. One of the Panthers biggest problems on Offense has been third down and long (3rd & 7+). By taking a sack, it is almost assured that the Panthers will find themselves in some sort of unfavorable down and distance scenario.
Over the past few weeks, Newton has done much better at avoiding coverage sacks, and finding targets downfield, highlighted by his 8.3 yards per attempt, although, this is one of the key areas of Cam's game to watch moving forward.