What’s Wrong With the 49ers Run Defense?

The 49ers are coming off a brutal loss to a Buffalo team that exposed a weak run defense. Today we look at what’s wrong with the 49ers run defense.

The 49ers are coming off a loss in which they gave up 313 rushing yards to LeSean McCoy and the Buffalo Bills. McCoy ran for 140 yards and three touchdowns while quarterback Tyrod Taylor and running back Mike Gillislee each had 60+ rushing yards. The Bills went on to win 45-16 in a fourth quarter blowout.

The 49ers turned the offense back over to quarterback Colin Kaepernick, who had an average day running and throwing ball. But the Kaepernick storyline overshadowed any criticism of the defensive performance, one that was a combination of bad tackling, weak scheme, and miscommunication.

I wrote about Jim O’Neil’s defense in Cleveland here, and we’re witnessing the same overall problems. Browns’ struggles were also highlighted midseason, which caused some alarm among players and fans, and concerns that fans now should not overlook:

“Recently, a number of players have told me what they believe is the main impetus behind the continual running-back beatings: The Browns have issues with gap integrity—football speak for jamming the holes between the offensive linemen.

Rather than being assigned specific gaps, Cleveland’s defensive linemen play different techniques based on how their offensive counterparts are blocking them. The linebackers, then, are expected to guess what technique their teammates are using, scrape through the resulting mess and make the play. Opposing offenses have identified this flaw on film and are repeatedly, week-after-week, gashing the edge of Cleveland’s defense. It’s a completely chaotic approach to stopping the run, and players have said—off the record—they’re spending way too much time thinking, and not nearly enough time reacting.

“It’s an entire guessing game,” said one source. “Imagine trying to define mud.”

The first major criticism examines both schematic weakness and the information overload Browns’ defenders complained about throughout the season and that 49ers players appear to be suffering from.

First quarter, 10:57, 2nd and 21 from the BUF 12

Buffalo lines up in shotgun with two running backs, two wide receivers, and a tight end inline with the offensive line. They run power to the left with the play side fullback as the lead blocker and the right guard pulling behind him into the hole.

49ers linebacker Aaron Lynch (#59) comes in for a delayed blitz just before the snap. At the snap, the tight end blocks down and eats Lynch’s rush easily. Linebacker Nick Bellore should automatically replace Lynch as the force defender.

Bellore reacts to the fullback block by attacking the outside shoulder of the blocker. In this case, he could have executed a wrong-arm technique by attacking the inside, or up-field, shoulder of the blocker and ripping through. By attacking the up-field shoulder, the wrong-arm technique bottlenecks the gap and prevents the pulling blockers from getting to the second level, spilling the ball carrier outside where the 49ers had two unblocked defensive who could’ve made the play.

Also, Lynch, recognizing the down block by the tight end, should “block-down, step-down” by replacing the tight-end and squeezing the C-gap, also spilling the ball carrier outside. The schematic weaknesses here enhance the technique problems. One way to adjust here is to move Buckner in the three technique over the top of the tackle in the four technique and two-gap the B and C gaps. If the four technique can hold the tackle and tight end double team, Lynch and Bellore could eat the blocks allowing a scraping linebacker or defensive free to make the play.

Second Quarter, 13:23, 2nd and 2 from the BUF 33

Another schematic weakness plaguing the 49ers is the unwillingness to make adjustments to the opponent’s formations. Buffalo lined up once in this heavy tackle over formation before this point in the game and the 49ers played it perfectly. However, in an almost identical set, the 49ers spread their defense evenly across the formation leaving the strong side of the offensive formation uncovered.

The 49ers had four on four from the center to their right and five on five from the center to their left. Buffalo runs counter trey to the right, creating a six on five blocking advantage for the offensive line due to the pulling left guard.

Arik Armstead (#91) squeezes the correct gap but his positioning could be better served by being head-up on the heavy tackle position and two-gaping the blockers. Lynch attacks the outside shoulder of the pulling guard, leaving Antoine Bethea (#41) exposed while he scrapes into the gap.

The rest of the defense follows the steps of the ball carrier rather than playing the ball. The result ends up being a 38 yard gain for McCoy only because he stumbles into one of his blockers down field.

Second Quarter, 10:24, 2nd and 4 from the SF 12

Buffalo lines up in a wildcat formation with McCoy taking the snap and motions into the heavy set with the two offensive tackles over to the right side and the tight end and guard to the left.

The 49ers make little adjustments and Buffalo runs power to the weakside with a pulling center and the fullback.

The blocking creates a four on four advantage for Buffalo due to poor alignment and technique.

Lynch would be better suited closer to the line. As he recognizes the block-down by the tight end, he could prevent the jump through to Bellore who tried to scrape over the top. This would allow Lynch squeeze that gap vacated by the tight end and wrong-arm the first puller. Instead, he attacks the outside shoulder of the pulling center.

Second Quarter, 3:10, 3rd and 20 from the BUF 26

Of course, not all of this can be blamed on O’Neil. Facing a 3rd and 20 in their own territory, Buffalo ran a draw to the left, only to have the entire 49ers defense collapse on a spot and miss several tackles enroute to a 22 yard gain for McCoy.

The 49ers rushed three defenders and have no backside contain for the eventual cutback. More troubling is that no defender got a hand on him until Rashard Robinson (#33) push him out of bounds after picking up the first down.

Fourth quarter, 10:59, 1st and 10 from the SF 18

The final example of run fits gone wrong comes from the 4th quarter. The Bills are in 21 personnel (two running backs, one tight end, two receivers) are running power to the right.

The defense breaks down immediately after Lynch sets the edge. Both Tank Carradine (#95) and Bethea attack the C gap leaving the play side B gap exposed for McCoy to run through. Bellore executes the wrong-arm technique on Bills lineman Richie Incognito spilling McCoy outside but no one is there to clean up the gap.

The defensive adjustments at this point were correct with the playside defensive lineman Ronald Blair (#98) playing head up on the tackle in the four technique. Was this a fundamental mistake caused by confusion or miscommunication? We’ll likely never know, but the important take away is we have witnessed similar blunders throughout the season thus far.

The Bills seemed to run at will on the 49ers with the power and counter gap scheme runs. The frustrating thing about that is O’Neil did not really make an attempt to adjust those unbalanced formations. He’ll need to simply what the defense does to counter Tampa Bay this weekend if the defense is to have any success.

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