With the Philadelphia Eagles having been eliminated from the playoffs on Saturday, the San Francisco 49ers are in the seemingly unique position of a hypothetical run to the Super Bowl consisting entirely of rematches from the regular season (I say seemingly because, honestly, I don't really know if it's that unique and it's not important enough to look up. So there.). After winning a heart attack-inducing game on Sunday in Lambeau Field against the Green Bay Packers, the 49ers will now prepare to travel to Charlotte to take on a Carolina Panthers team that handed them their third loss of the season back in Week 10.
The dominant storylines coming out of that Week 10 loss focused on two narratives: 1) Carolina had out-muscled a San Francisco team who's calling card has been their physicality and ability to dominate the line of scrimmage on either side of the ball and 2) the 49ers had serious questions to ask about their passing game when facing a quality defense. Offensively, it was the 49ers worst performance of the season as they were limited to a season-low 2.9 yards per play and a DVOA of negative-54.2 percent, the lowest mark of the Harbaugh era.
There are some obvious caveats to get out of the way. First, Michael Crabtree had not yet returned from the Achilles injury that forced him to miss the first 11 games of the season. Since Crabtree has been reinserted into the lineup, San Francisco's passing offense DVOA has been above 30 percent in all but one game. And second, Vernon Davis left the game with a concussion midway through the second quarter. Anquan Boldin has had a very good season as Colin Kaepernick's primary target, but it is Davis that makes the passing game go. His ability to stretch the field vertically is an element that no one else on the 49ers' roster can replicate.
With both Crabtree and Davis back in the lineup, shutting down the 49ers offense in the fashion the Panthers did in Week 10 is a much more challenging task. But that doesn't mean there aren't things we can learn from the first matchup between these two teams.
San Francisco's game plan was to use a heavy amount of two back, two tight end packages. By my count, the 49ers used three receivers on about 38 percent of their offensive snaps, but those came almost exclusively in third and long situations and their two minute drive at the end of the first half. When game situation wasn't dictating otherwise, it was a whole bunch of 22 (2 RB, 2 TE, 1 WR) personnel. Once Davis left the game, that transitioned into 21 (2 RB, 1 TE, 2 WR) personnel with Adam Snyder occasionally entering the game as the de facto second tight end when the 49ers wanted to use their 22 personnel looks.
This allowed the Panthers to spend the majority of their defensive snaps in their base 4-3 front, which just so happens to be the strength of their team. Carolina's game plan was simple, but incredibly well executed; they wanted to stop the run while taking away the deep passing concepts that San Francisco prefers to throw. Let's go to the All-22 and see how they were able to accomplish that.
Overloading the strong side
The 49ers have an incredibly strong tendency to run the ball towards the motion player, which frequently happens to be the strong side of the formation. Most plays in San Francisco's offense features some type of motion or shift prior to the snap. The last player to go in motion – whether that's a fullback, tight end or extra offensive lineman – usually is a good indication of the direction the run is going. There are benefits to doing this. This motion often comes late in the play clock and if the defense fails to adjust, they can end up outnumbered on the play side giving the 49ers the edge they're looking for. If the defense is prepared for it they can negate that advantage and occasionally create some negative plays in the process.
Carolina's answer to this was to shift their linebackers towards the motion player and use strong safety Quintin Mikell as an extra linebacker on the weak side. It started more subtly, but by later in the game the Panthers were shifting their entire linebacking trio to one side of the center. The image above shows how the 49ers were aligned prior to any motion. They're in 22 personnel with Adam Snyder filling in as the second tight end. Vance McDonald motions to the left of the offense, triggering a shift by all three of the Panthers' linebackers in the same direction.
This shift allows the Panthers' front to match the number of blockers the 49ers have on that side of the field. On top of that, immediately following the snap, all three of those linebackers begin moving downhill towards the left of the offense, clearly anticipating the run in that direction. Defensive end Greg Hardy makes the mistake of making a move inside rather than keeping contain on the outside and impedes Luke Kuechly's movement in the process, allowing Frank Gore to bounce the run to the outside and pickup a short gain before getting taken down. Had that not happened, this play likely goes nowhere.
On the surface, it would appear that the 49ers were able to run the ball somewhat effectively. They finished the game with 105 rushing yards at a 4.4 yard per carry clip. However, it was a very inconsistent 105 yards. Including a 16 yard scramble by Kaepernick, the 49ers had six runs of over 10 yards. They also had six runs that went for no gain or a loss. In all, they had a success rate (the percentage of runs that picked up sufficient yards towards converting a first down, based on down and distance) of 33 percent leading to a rushing offense DVOA of negative-18.6 percent. Outside of a handful of runs, Carolina shut down the running game and they did it with a strong front seven and good play recognition, successfully anticipating where San Francisco wanted to go in the run game.
Pressuring Kaepernick and preventing the big play
Even with their success in slowing down San Francisco's rushing attack, where Carolina really did their damage on defense was in putting the clamps on Colin Kaepernick and the passing game. By practically any measure you can come up with, it was Kaepernick's worst day as a pro. He completed just 50 percent of his passes, was held under 100 yards passing and was sacked six times.
The Panthers did a fantastic job limiting the 49ers on first down. San Francisco's 22 first down plays averaged just 2.73 yards per play, well below their seasonal average of 5.41 yards per play. This set the 49ers up with difficult third downs all day long that they were unable to convert. A large reason for the success the Panthers defense had on first downs was their ability to get pressure on Kaepernick. Of the six sacks he took on the day, five of them came on first down. Needless to say, those types of negative plays to begin a series are difficult to overcome. This play from late in the second quarter is a fantastic example of the problems that Carolina presented in the passing game throughout the day.
San Francisco is in two minute mode here and has their 11 personnel (1 RB, 1 TE, 3 WR) on the field aligned in a Shotgun Trips formation. Carolina matches with their nickel package. The 49ers are looking to attack down the field with a four verticals call on the play. It's a play that San Francisco runs a fair amount of from a variety of different formations and personnel groupings.
As they did for much of the day, the Panthers are playing a three-deep coverage with the intent of keeping everything in front of them. Free safety Robert Lester is 20 yards from the line of scrimmage to begin the play and each of the corners bail at the snap, looking to stay over the top of the receivers to their side. Even so, the 49ers should have an advantage as they have four receivers going down the field against only three deep defenders. The problem is Kaepernick waits too long for the routes to develop and isn't able to deliver the ball before taking the sack.
The Panthers have a weak side blitz called. Linebacker Thomas Davis and safety Michael Mitchell both blitz from the right side of the offense with defensive end Greg Hardy dropping into an underneath zone on the opposite side. The 49ers end up sliding their protection to the left, giving the Panthers an overload on the right side. Gore picks up Davis, but with three offensive lineman left blocking one defender on the left side, Mitchell flies through untouched for the sack.
Kaepernick has options on the play. As you can see in the post-snap image above, before Mitchell gets to the line of scrimmage the ball should be coming out to Vance McDonald, who is just clearing Hardy and breaking open across the middle. But because Kaepernick doesn't throw with anticipation, the pressure is able to get home and the 49ers lose the opportunity to get points before the end of the half. A very similar scenario played out on San Francisco's penultimate possession of the game.
On this play, we see each team in base personnel; the 49ers with 21 personnel and the Panthers in their 4-3. San Francisco is again looking to attack down the field, this time with Boldin and McDonald on the right side of the formation. McDonald is going to run up the seam with Boldin running an out and up from a condensed split. Carolina is running a very similar defense to the last play we looked at. Again we them in a three-deep coverage, three underneath defenders and a five-man pass rush.
The route combination from Boldin and McDonald is designed to attack cornerback Captain Munnerlyn in his deep third zone. If Munnerlyn stays to the outside over the top of Boldin, McDonald will be open up the seam – especially considering the depth of the safety. If Munnerlyn cheats inside to help on McDonald, Boldin will be open up the sideline.
After the snap, the 49ers again get an advantageous look down the field. Defensive end Charles Johnson drops into coverage and ends up in no-man's land between McDonald and Bruce Miller in the flat. Both players are open and with Kaepernick looking that direction at the start of the play, it should be a quick throw. When Kaepernick hesitates and doesn't pull the trigger, the pressure concept from the Panthers comes through again.
Other than Johnson, who drops into an underneath zone, the rest of the Panthers defensive line slants towards the right of the offense with linebackers Davis and Kuechly blitzing off the back side. Jonathan Goodwin and Mike Iupati each struggle with their slanting defender, allowing them to get enough penetration to cause Kaepernick to move within the pocket. When he moves, he moves right into the path of the blitzing Kuechly and has nowhere to go.
The Panthers didn't bring more than four pass rushers often – only 9 times in 31 dropbacks according to Pro Football Focus – but they were effective when they did, picking up three sacks and only allowing 17 yards on three completions when Kaepernick was able to get rid of the ball. Knowing that Kaepernick wanted to push the ball down the field, Carolina frequently sacrificed underneath coverage in order to stay over the top and prevent the big play. They frequently kept a safety 20+ yards beyond the line of scrimmage and they predominantly played three-deep zone coverage, as we saw in the two plays highlighted above. They were confident that taking away the deep routes Kaepernick prefers to throw would give their talented front enough time to bother him.
The six sacks combined with the fact Kaepernick completed just one pass more than 10 yards down the field showed that Carolina was extremely successful with this approach. Kaepernick routinely chose to forgo an open underneath option to wait for something to develop further downfield. The additions of Crabtree and Davis will certainly have an impact, but if the 49ers are to go into Charlotte and come away with a victory this weekend, Kaepernick must be more decisive.