A year ago, the 49ers struggled to get to the quarterback with their front-4. For a defense that didn’t like to blitz often, this was a problem. Opposing quarterbacks had little resistance moving the ball against the Niners and collectively put up MVP-type numbers (35 TDs, 2 INT, 105.4 QB Rating).

Fast forward to 2019, and San Francisco’s front-4 is arguably the best pass-rushing unit in the NFL. The 49ers are 3rd in the league in sacks and have held opposing quarterbacks to a meager 65.7 passer rating, good for 2nd lowest in the NFL. The pass rush has put consistent pressure on opposing offenses, leading to more takeaways (16 through 8 games after generating just 7 in all of 2018).

The additions of Dee Ford and Nick Bosa are obvious reasons for the improvement. The increased commitment to using a Wide-9 technique is another contributing factor. The Wide-9 gives defensive ends an advantage in rushing the passer. It creates better angles for winning against offensive tackles off the edge, as you can see below.

Focus on Dee Ford, aligned on the defensive left.

You can see that Ford was able to rush on almost a straight path to the quarterback because of his initial alignment.

That angle makes it difficult for an offensive tackle to push his man around the pocket. Instead, it sometimes becomes a race to a spot between an explosive defensive end and a much less athletic offensive tackle. The advantage was all in Dee Ford’s favor here.

Below, you can see a similar example with Nick Bosa.

You can see from this play that quarterback Kyle Allen had less space to step up in the pocket. The combination of Bosa’s angle and the rest of the interior defensive line bringing a relentless rush (as the Niners have all year) created no escape lanes for Allen.

The angle created by the Wide-9 can also make it easier for the pass rusher to dip his shoulder around the edge without losing his leverage and balance, even if the tackle is able to get to him and impede his path initially. Watch Dee Ford below.

The Wide-9 can even make it easier to drive through the tackle with bull-rushes or speed-to-power moves, given the extra steps the defensive end has to build up momentum.

For a defense that doesn’t blitz frequently, the ability to generate a pass rush with its front-4 is critical. The wide-9 is certainly important in enabling an effective rush. Finding ways to create advantageous matchups is another. With the talent that San Francisco suddenly possesses up front, they have had more opportunities to do so.

Take this play against the Browns. The 49ers aligned with defensive ends Dee Ford and Nick Bosa next to each other. Defensive tackle DeForest Buckner (12.0 sacks in 2018) was aligned in the A-gap to the same side of the formation.

Buckner crossed the center’s face, taking him with him and ensuring there was no help inside for the left guard and tackle on Bosa and Ford. Because Bosa and Ford are sick men who like to toy with offensive linemen, they ran a stunt.

Baker Mayfield had no chance on this play.

The addition of Bosa and Ford has enabled the 49ers to create a formidable 3rd-down pass rush. The Niners like to mostly use Bosa and Ford on the outside, with Buckner and Arik Armstead inside. Armstead is a defensive end, and moving him inside helps generate athletic mismatches against interior offensive linemen. This is especially true given that Bosa, Ford, and Buckner garner so much of the protection’s attention. Take the below play, where Armstead got matched on left guard Jamil Demby, as an example.

Armstead has been reaping the benefits of these interior matchups. He already has 5.5 sacks after finishing last season with just 3.0. All but one of those sacks have come on 3rd down with him aligned inside.

The transformation of the 49ers’s defensive line is the key reason they are a drastically improved defense in 2019. Opponents are in a true pick-your-poison situation. At least one of Bosa, Ford, Buckner or Armstead will always get a 1-on-1 matchup. The 49ers’ 8-0 start becomes less surprising the more you watch this group on film.

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