As is often the case, this game was decided by a few key plays. The defense gave up two huge plays (one on each of the plays we highlighted in our preview of the matchup) at perhaps the worst times possible. Just when the momentum was shifting after a UNC score and defensive stop, the Heels fumbled the punt. Key (and in a couple cases, stupid) penalties cost the offense the ability to finish drives. Every time the momentum seemed about to shift, the Heels were unable to get over the hump, unprepared to make the big plays when they counted.
The good news is that aside from those two big plays, the defense was able to limit South Carolina more overall than I expected. The first score was on perhaps Spurrier's favorite pass play, "Mills" (named after former Florida Gators star Ernie Mills). After giving up some early rushing yards, UNC lined up in a basic quarters coverage, with four defenders each responsible for a deep 1/4 of the field.
"Mills" is especially good against quarters, because the "dig" route from the inside receiver typically causes the frontside safety to step up, creating a one-on-one matchup for the post route against the corner. As a result, the corner must read the release of the inside receiver—if that receiver releases vertically, the corner must maintain inside leverage because he will not have deep help from the safety against the post.
Corner Tim Scott, however, did not maintain his leverage, allowing the receiver inside. Looking at the photo below, Scott should be inside and over top of the receiver about where the red box is.
Once the receiver gets inside, it's an easy throw for the quarterback and a nearly impossible recovery for the cornerback, as the receiver is running away from him towards the football, with his body between the corner and the target. Connor Shaw had a clean pocket and made a perfect throw, hitting Shaq Roland in stride, and the Tar Heels found themselves down a touchdown right out of the gate.
There has been much forums discussion in the wake of this loss about the viability of UNC's 4-2-5 defensive approach, but this was not a situation where the defense was blitzing or in an especially vulnerable look. Every team in the country plays quarters coverage quite regularly. The key here is that the Carolina secondary did not play with good fundamentals, while there was little to no pressure on the quarterback making the throw.
Mike Davis's 75-yard run involved a similar breakdown from the secondary. The front seven got better over the course of the game and did their jobs on this play, as Vic Koenning's defensive philosophy here is to "spill" the ball to the outside, where the defense should have multiple players with good angles to make the tackle.
It's clear from these photos that the front did its job, compressing the running lane. This should have been no more than a two yard gain, but corner Jabari Price and safety Tre Boston took terrible angles, turning a good defensive play into a 75-yard backbreaker.
The bigger problems were on offense. I don't think very many people—I certainly didn't—anticipated the UNC offense being limited to 10 points, and even a great game from the defense would not have been enough to win with that output.
As we had anticipated in our previews, Jadeveon Clowney was largely neutralized by the combination of quick passes and a solid game from tackle James Hurst, and UNC's running backs were able to find some running room. In spite of that, the Heels were unable to stay ahead of the sticks and avoid long-yardage situations, which was the primary key to the game on offense.
The problem was that South Carolina was able to press and play physical on the outside while not giving up the big play downfield. In previous articles, we've discussed the importance of looking at yards per attempt to measure efficiency, and a quick look at Bryn Renner's stat line shows the problem: 43 attempts for 194 passing yards, a paltry 4.5 yards per attempt, a reflection of UNC's inability to beat South Carolina's press coverage down the field for big plays.
Tar Heel receivers struggled to get off the press and get separation downfield, and Renner missed several key throws when receivers were open (such as the overthrow to Ebron down the sideline in the early second quarter). Renner never looked fully composed to me, as his footwork was all over the place in the pocket, leading to too many passes that sailed due to poor weight shift. Fortunately, that should be fixable.
Romar Morris looked terrific, and UNC was able to run the football effectively at several points in the game.
Although it was a 17-point loss, the talent gap was not nearly as big as the gap on the scoreboard. UNC simply showed its lack of big-game experience and lack of composure at key moments. Despite the loss, this experience should make this team better.
The defensive front looked improved from last year, and Norkeithus Otis and Darius Lipford showed a lot of athleticism and physicality at the Bandit position. South Carolina is one of the most physical rushing teams in the country, and the defensive front held its own better than I had expected (South Carolina averaged 4.1 yards per rush aside from the 75-yarder).
The secondary, however, got exposed both against the run and the pass. Poor angles and fundamentals from the secondary led to both long scores, and the Heels lack a difference-maker (and recovery speed) in the secondary.