From Weeks 1-12 of the 2019 season, only the New England Patriots could claim to have a better pass defense than the San Francisco 49ers, and that’s only because the 2019 Patriots were (and are) playing pass defense at a historically great rate. But the 49ers, led by defensive coordinator Robert Saleh, weren’t far off. From Weeks 1-12, San Francisco allowed opposing quarterbacks to post a QBR of 72.50, and only the Patriots were better at 50.55. The 49ers allowed a Positive Play Rate (plays in which the Expected Points Added were above zero) of 37%, and only New England was better at 36%. Per Sports Info Solutions, the 49ers’ defense saved 188.5 points below the average, and opposing offenses had minus -140.3 EPA against them. Again, only the Patriots were better in either category.
No defense allowed fewer completions (198) or passing yards (1,854), and though there was a vulnerability in touchdowns allowed (11), matching the interception total with 11 seemed to make that problem go away. The 49ers were 10-1 after 12 weeks, their only loss in overtime to Seattle, and the defense was the biggest part of that success equation.
Then, regression happened in a big hurry. The 49ers went 2-2 in their next four games, including a Week 15 loss to the Falcons that put everybody on alert. Losing 20-17 to the Ravens is one thing, but allowing Matt Ryan to complete 22 of 34 passes for 234 yards, two touchdowns, and no interceptions in a 29-22 stunner? Well, that’s not the act of a top defense. And over the last month, the 49ers’ defense has been anything but.
San Francisco has had a Positive Play Rate of 49% in that time. Their opposing QBR allowed has jumped to 102.39. They’ve saved 15.3 points above the average (the Packers have led the league in that time at 81.1), and their EPA of 24.3 is the fifth-worst in football, behind the Lions, Jaguars, Raiders, and Giants. They’ve allowed 95 completions for 987 yards, 10 touchdowns, and just one interception over that 2-2 stretch. Basically, the team that will take the field once again against the Seahawks this Sunday in hope of gaining the first overall seed in the NFL playoff picture has a defense playing like you’d expect from a team awaiting a top 10 slot in the draft.
Pass rush has certainly been a problem. From Weeks 1-12, San Francisco led the NFL with 45 total sacks, and 4.09 sacks per game. And while they were in the middle of the pack in quarterback hits (71) and hurries (109), the extent to which Nick Bosa and his buddies on the defensive line were able to demolish the intentions of enemy quarterbacks went a long way to disguising those other numbers.
Over the last four weeks, it’s been a very different story. San Francisco is tied for last in the league with the Browns and Seahawks with just three total sacks, and though they’ve kept the hits and hurries going to the point where the team’s overall pressure percentage has gone up from 29.67% to 31.06%, those pressures are not leading to breakups of big plays. Quite the opposite.
And as is the case with most Legion of Boom-style defenses, this one doesn’t blitz a lot. The 49ers have the fourth-lowest blitz percentage in the NFL at 20.3%, which was fine when they were getting home with just four defenders. But that’s not happening now, and the pressure/coverage schism is negatively affecting both sides at the worst possible time.
Injuries have also played a factor. That the 49ers’ pass defense has declined severely at the time time the team has been missing safety Jaquiski Tartt is absolutely no coincidence. Tartt suffered a broken rib in the team’s Week 13 loss to the Ravens, and the hope is he’ll be back for the Seattle game. He’s been the team’s best safety this season, allowing just 13 catches on 25 targets for 98 yards and one touchdown all season, and the efforts of Jimmie Ward and Marcell Harris have not matched up.
Saleh was also without Richard Sherman after the veteran cornerback suffered a hamstring strain against the Saints in Week 14, missed the Falcons game, and returned in Week 16 against the Rams. Sherman has been one of the five best cornerbacks in the NFL this season, clamping down on enemy receivers, so the absence of these two great players would go a long way to explaining the current malaise. Not to mention the losses of edge-rusher Dee Ford, who’s been out with a hamstring issue since Week 14, and linebacker Kwon Alexander, who was lost for the regular season to a torn pectoral in early November.
The result of all this? Plays like this 10-yard touchdown pass from Jared Goff to receiver Brandin Cooks in San Francisco’s 34-31 win over the Rams last Saturday. Cooks gets free to the left uncontested, linebackers Fred Warner and Dre Greenlaw bite on Goff’s boot-action, and three defenders follow Robert Woods on his crossing route. Cornerback Ahkello Witherspoon gets close near the end of the play, but not close enough. When this defense isn’t reading correctly, there isn’t really a lockdown scheme, or a current group of healthy players, in line to make up for it.
Warner’s 46-yard interception return for a touchdown near the end of the first half was one example of how this defense works as it’s supposed to. The four-man line compresses the pocket, forcing Goff to make an off-platform throw. Warner reads the quick pass to running back Malcolm Brown all the way, and that’s that.
There is another vulnerability the 49ers defense has, and opposing offensive coordinators are starting to go after them heavily to attack it.
According to Saleh, the Rams called 21 boot-action plays against his defense last Saturday, which Saleh called “unheard of.” Throwing boot concepts at a defense with a fast, aggressive defensive front forces defensive linemen to make second reactions when they’d rather not. It forces linebackers to sail betwixt and between run fits and coverage adjustments. The routes receivers run in boot concepts, which can be improvisational in nature at times, force cornerbacks and safeties to recover from their original concepts to what they’re actually facing.
Sports Info Solutions charted Goff with 18 boot-action attempts, completing 11 for 131 yards, 61 air yards, and that touchdown pass. In Week 16, Ryan Tannehill of the Titans ranked second in the NFL with five boot-action attempts. So, yes, it was highly unusual. And yes, Saleh should expect the Seahawks to run heavy boot until and unless his defense can stop it. In Week 10, Wilson attempted seven passes on boot-action, completing six for 50 yards, 23 air yards, and this touchdown pass to tight end Jacob Hollister.
“I always look at how teams call games against us,” Saleh said on Thursday. “If a coordinator is deliberately changing the way he’s called games versus other opponents versus us, then I feel like, heck yeah, it’s affecting them because they’ve had to actually change their game plan and change the way they approach us. Last week would be a perfect example. To call 21 boots is unheard of, not unheard of, obviously, but I think we’ve had 25 or so boots all year and to get it 21 times in a game tells me our rush is still very effective, teams are still worried about it. And for us, we’ve just got to continue to be cognizant of it and be able to go with the flow of the game and the way the coordinator’s calling plays and make adjustments as quickly as we can.”
Saleh’s defense was able to compress Goff’s half-field reads off boot-action in the second half, but Wilson presents another type of challenge entirely with his own ability to roll out, improvise, and combine velocity and accuracy to unravel the defenses he faces. And if Wilson attempts somewhere in the neighborhood of 10-15 boot throws, don’t be at all surprised. It’s also one sure way for Wilson to offset the effects of his own leaky and injured offensive line against San Francisco’s furious pass rush, such as it’s been of late.
“I still think teams are going to do whatever they can to protect their quarterback, which was very evident on Saturday night,” Saleh said. “They’ll still be rolling out, boots, sprint pass, whatever they can, quick game, get the ball out of the quarterback’s hand. We’ve just got to be quick to make the adjustments that we need or get the calls that we need. If they want to continue running them then keep running them. Even when you go back and watch them, we get so many boots from our office during training camp and OTAs. When you actually watch the structure of how it was being defensed, we were very clean. For the most part, guys were covered. The quarterback just kept leaking for another four or five yards or whatever, but I wouldn’t put it past teams to continue trying it.”
Okay — so what’s the counter to that?
“Obviously you want to be tighter in coverage, but if a team is running quick game you want to be able to contest all of those and see if you can bat a couple at the line of scrimmage, see if you can bat a couple at the back end. And if your yards per attempt are less than, I think the number is six and a half, you’re one of the best in football. If teams want to dink and dunk at four yards, we trust that we’ll be able to knock one down, we’ll be able to get a PBU, we’ll be able to disrupt the flow of your drive to get you to a third and advantageous for us so we can get off the field. Teams don’t always want to take those check downs, but if that’s the case then we’ve just got to continue to play tighter coverage in the back end and understand up front that the ball is coming out quick to get our hands up.”
So, a combination of better pass rush and tighter coverage. Which works in theory — the 49ers are eompletely capable of playing Cover-1 or 2-Man with their personnel and locking down on enemy receivers. That’s all well and good until and unless you’re attacked with deep crossers in a man blitz, and Witherspoon can’t keep up with Cooper Kupp, resulting in an easy 22-yard touchdown.
“The crossing route? For me, I always try to look inward,” Saleh said of Witherspoon’s coverage. “That one was a hard one for him. You’re in man pressure, there’s no low hole help, it got eaten up. The way they worked, I call it a runaway route. For me, it’s a very, very hard down for a corner on that one. I always look inward. I feel like I could have helped him a little bit better. At the same time, we’ve got to play with better technique and all that stuff. It was just a simple runaway route and man pressure that had no low plug help and it didn’t get home.”
And now, here comes Russell Wilson again — the first quarterback to beat Saleh’s defense back when it was performing at an optimal level; you could argue that Lamar Jackson was the second. Wilson completed 24 of 34 passes for 232 yards, one touchdown and one interception, adding 53 rushing yards on six attempts. Wilson faced a gauntlet, but as has been his wont throughout his NFL career, he found weak spots and adjusted. Now, the weak spots seem to be springing up everywhere, putting the pressure on Saleh to counter-punch.
“You have to be respectful to the level of the quarterback when you’re around the edge,” Saleh said of the challenges Wilson presents. “You have to be respectful to the pocket push and what could happen and being tied together and what could happen if one of your guys takes an outside move and what you need to do to counter it. But at the same time, you don’t want to handicap your guys into being so worried about where this guy’s rushing that it just becomes what I call a mush rush where no one is really getting off their blocks and getting to the quarterback.
“You’re very cognizant of your rush lanes and you still rush to go get the quarterback and understand what he likes to do, what are his tendencies, where does he like to escape, and you just play ball from there. Understand, he will break the pocket a couple of times. We’ve just got to be great in the backend. Be relentless in what we call plaster rules. Just being relentless with our plaster rules and making sure that when he breaks the pocket we find a man and stick with him. The front just has to remain relentless in their pass rush and understand that the play’s not over until the whistle blows.”
The 49ers did have success blitzing Wilson with Warner and cornerback K’Waun Williams, so there could be more of that this time around.
“Yeah, because you always feel like you’ve got to do something,” Saleh concluded. “You’ve got to be a little bit different. They’re expecting certain things and you’ve got to be able to mix in what you did, mix in some other things. There’s always a self-scout study that you’ve got to put to it, but at the same time it’s not like you can reinvent the wheel every week.”
Saleh may not be able to reinvent the wheel with the personnel he has, but new wrinkles will be the order of the day. Without them, the chances of Seattle beating his defense for the second time this season — and taking the NFC West as a result — will increase exponentially.
