In the first article breaking down the Super Bowl loss, we focused on the offense, the plays that Jimmy Garoppolo missed, and whether or not Kyle Shanahan’s playcalling in the late first half and fourth quarter made a difference in the outcome. Today, we’ll look at the defensive side of the ball and what contributed to the late collapse.
The 49ers defense dominated their opponents in the playoffs, only allowing one touchdown to the Vikings and a couple of late touchdowns to the Packers who never really threatened a comeback outside of that. The Chiefs offense were late starters through two games in the divisional round against the Texans and championship game against the Titans.
In the Super Bowl, the 49ers defense did what they wanted to for three and half quarters: the limited the Chiefs offense to just 10 points and nearly 34 scoreless minutes between their second-quarter field goal and their mid-fourth-quarter touchdown. And they did so largely by playing what Scott Geelan and myself suggested would be the case based on prior film study of Chiefs opponents plus 49ers tendencies throughout the season.
Basic defensive structure of the 49ers gameplan
They would intercept quarterback Patrick Mahomes twice in the second half, but only turning one those interceptions into points. On Late in the game, the 49ers kept with a coverage plan that worked for them through most of the playoffs and regular. On first down, the primary coverage was “poach/solo” coverage, a common form of quarters/cover-6 against trips 3x1 where the opposite safety away from the trips has responsibility for all of #3 vertical.
The rest of the time, according to USA Today’s FTW Steven Ruiz, the 49ers played quarters 93% of the time when the Chiefs lined up in 2x2, played cover-1 on third-and-3+ 80% of the time, and played primarily cover-3 buzz in 3rd-and-long situations.
Two of the ways the 49ers defended 3x1 trips this year was with the addition of cover-6 or “poach”/”solo” coverage and with cover-3 buzz away from the passing strength. Both coverages allow the defense to rotate toward the trips or passing strength to get defenders underneath or over the top and remove any vertical from the inside #3 receiver.
Poach/solo allows a defense to maintain a 3-over-2 in coverage against the trips if the #3 receiver in the formation runs a vertical across because the safety to the weak side will match the vertical coming at him. This allows the other safety to sit over the top and midpoint potentially two vertical routes with defenders underneath in a bracket.
In cover-3 buzz, that safety opposite the trips in the 2-high shell that would normally defend vertical routes from the #3 will still look for #3 vertical across but will do so from a hook zone rather than a 2-high zone, meaning that he will rotate down to almost linebacker depth and rob anything coming across.
This means that the deep safety shaded to the trips needs to push to the deep middle third to compensate for this rotation, leaving the defenders over the trips vulnerable to 1-on-1’s from the #1 and #2. Typically, the 49ers would then tag a “zebra” 1/3 call to their trips corner that tells him to midpoint #1 and #2, meaning that he’s inside and over the top of potentially two verticals and can peel off to either receiver when the ball is thrown. The Rodger’s interception is an example of this.
For most of the game, the 49ers played the first coverage mentioned above, poach/solo. And it worked, limiting the Chiefs offense to a dink and dunk offense, allowing the 49ers get pressure on nearly every snap, though the Chiefs did pick up nine first downs while the 49ers played poach/solo.
The 49ers counter to the Chief’s vertical crossers was to have the safety sit in 2-high opposite the trips and match the vertical coming at him. This play went for a minimal gain as it was likely to assess how the 49ers might counter the 3x1 play calls for the rest of the game.
You can see in the structure of the defensive play call that the safety, usually Jaquiski Tartt, looking for a vertical crosser while sitting in his zone on the hash, allowing Jimmie Ward to roam over the top in support of his two defenders underneath, forcing Mahomes into short completions, a sack, or scramble vice giving up a big play.
Later in the quarter, the 49ers were able to pressure Mahomes and get a sack using the coverage as Mahomes had nowhere to go on a condensed field with verticals inside the 15-yard line in the red zone.
In the 4th quarter here in the below video, the defense can defend against the pass but isn’t able to keep Mahomes from scrambling for nine yards and a first down. But you can see again in the structure how effective the coverage is erasing Mahomes’ reads, especially late in the down.
The one weakness to playing this match coverage is that receivers can run off the underneath defenders and widen them enough to let Mahomes scramble for a first down because there are no effective pursuit lanes or angles to take. Matching the receivers routes puts them 12 yards downfield, and they are unable to make up the ground to contain the quarterback. Despite that, the coverage was effective at limiting the big-play potential.
Chiefs quarterback Patrick Mahomes threw one interception against cover-3 buzz because the 49ers secondary was able to blanket the Chiefs route distribution and rotate to cover another intermediate to deep route outside the hash.
First interception: 3rd quarter, 3rd-and-12 at KC 39, 5:36
The Chiefs are operating out of the gun in 11 personnel and look to get Mahomes rolling to his right to see if they can hit the deep curl between the hash and numbers while the 49ers defense rotates toward the sideline.
It was a gamble given that the coverage rotated to the passing strength under a cover-3 buzz rotation.
Mahomes executes a quick play fake that briefly holds the linebackers in place before they rotate their coverage. Warner rotates to the strong hook with eyes on Hill and Mahomes. He sees Mahomes pull up to throw and sits in his zone, cutting off Hill’s path to the ball and picks it off.
The Chiefs may not have been content to give up the interception, but they did get a piece of information they could use later to set up the 3rd-and-15 play later in the fourth quarter. Hill’s route had him selling the corner before cutting inside to the post before he decided to sit his route. Ward, in deep middle third responsibility, opened up toward the sideline with Hill’s move to the corner, prepared to drive on it if necessary.
That tidbit would reveal to the Chiefs that Ward would open toward a given cut because he has to defend that space as he is the last line of defense and has to respect Hill’s.
Second interception: 4th quarter, 3rd-and-6 at SF 23, 12:05
The 49ers forced a second interception under cover-1 “robber” rotation against the Chiefs triple slant concept to the left out of a 3x1.
Ward is shaded over the 3x1 to help over the top on anything that goes deep. Tartt is the opposite half safety playing a “robber” technique and watching for the deep crosser.
Mahomes drops back to pass and gets rid of the ball quickly on his 1-step drop. The throw was behind Hill, and Tartt lays the hit on him as the ball deflects off Hill and into Tarvarius Moore’s hands for the interception.
Missed opportunities late on defense
Remember the first interception above? The one time the 49ers defensive play call burned them was in calling cover-3 buzz to trips instead of their cover-6 poach/solo call. This is where the Chiefs capitalized on the information they gathered from that play, as well as the first quarter throw above that quarterback coach Mike Kafka said they adjusted to.
The play gained 44 yards on a 3rd-and-15 and kept the Chiefs in the game, allowing them to score and cut the lead to 20-17.
The play call was a deep dig with a fake over route that turned into a post corner route. It’s a play that is designed to take advantage of the cover-3 match rules the 49ers play or against cover-1 man coverage.
The first play, 3 jet wasp, was the play that effectively changed the game. And it was a big play for the chiefs in the 2019 AFCCG against NE. It's a good play against single high coverage. pic.twitter.com/AHQjKqIGRn— rich (@richjmadrid) February 12, 2020
It was a play the Chiefs ran in the AFC Championship game against the Patriots the previous year for a big play of 40+ yards. It’s a slow developing play that Mahomes has to have the patience for coming open at the right time.
The 49ers are in their disguised cover-3 with the buzz rotation by Tartt down away from the trips. This allows the defenders to rotate toward the trips, but the free safety must compensate for the safety rotation down to the hook zone. Corner Emmanuel Moseley looks to be making some kind lock alert call that tells Ward he’s going to match #1 vertical instead of playing a zebra 1/3 midpoint.
At the snap, Ward vacates the hash and drops to the middle of the field as the routes develop. #1 goes vertical, so Moseley matches the deep dig across. Tyreek Hill (No. 10) in the middle slot runs vertical and angles across, sells the post, so Moseley stays on #1 and then cuts back toward the sideline while Ward is in mid-turn to get back over to the far side of the field.
The pass rush is unable to get home, and Mahomes has nearly four seconds from the snap until he throws it. He completes the pass for a 44 yard gain on third down. The Chiefs would cut the lead here and then eventually overtake the 49ers after they were unable to keep the chains moving.
In a game with plenty of blame to around, the defensive collapse was spurred in large part due to the predictable play-calling of Robert Saleh. Mahomes missed early and semi-often, and that was a testament to all elements of the 49ers defensive gameplan. Late in the game, Reid gambled against Saleh’s defensive calls, and Mahomes hit the jackpot for him, cashing in on two deep throws that cut the lead and led to the go-ahead score.
They kept Mahomes guessing and late in the game Saleh should’ve adjusted for a potential vertical threat that wasn’t really there early on for the Chiefs but was to be expected with them trailing 20-10. The structure worked all season behind the league’s most dominant pass rush, but in a close game against the league’s best offense, that was more of the difference on defense than anything else that led up to it.