49ers-Bears preview: Focusing on read option, and NaVorro Bowman, Aldon Smith absences

There’s a good chance than when you think of San Francisco 49ers and the Chicago Bears, the first thing that comes to mind is defense.

For the Bears, that defense-first identity is something that extends back as far as the franchise as been in existence. For the 49ers, a dominant defense has led the way in the team’s most recent run of success. When the two teams most recently met during the 2012 season, much of the pre-game talk centered around how back-ups Colin Kaepernick and Jason Campbell were likely to struggle against two of the league's premier defenses. It wasn't too long after that game that the identity of each team began to shift.

Last season, the 49ers finished with a better offensive DVOA ranking than defensive DVOA ranking for the first time since 2006, when neither was very good. You have to go back another decade to find a season when that happened for the Bears prior to 2013. Now, as these teams prepare for another Sunday Night Football match-up, it’s under considerably different circumstances than when they faced two seasons ago and each of these once dominant defenses faces serious question marks.

Death of the read option?

The Bears fielded the worst run defense in football a season ago, getting gashed by opposing run games to the tune of 5.3 yards per carry. With the likes of Henry Melton, D.J. Williams, and Lance Briggs all missing significant action, injuries certainly played a large role in Chicago's plummet from first to worst against the run.

Bears' general manager Phil Emery didn't sit by idly, as he put just about all of the team's available resources in the offseason towards the defense with heavy emphasis on the front four. Defensive lineman Jared Allen, Lamarr Houston, Jay Ratliff, and Willie Young were brought in during free agency with Chicago adding two more players up front in Ego Ferguson and Will Sutton with two of their top three selections in May's draft. In all, only Stephen Paea managed to keep his job from the unit that performed so poorly in 2013.

It's incredibly early in the season to be forming conclusions on the success of those moves, but early returns have not been great. The Bears allowed nearly 200 yards on the ground at five yards a pop in Week 1 against the Bills. Buffalo's offensive line consistently got push on the interior of Chicago's defense, rushing for 78 yards on 10 carries between the guards according to Pro Football Focus.

That performance certainly doesn't bode well for the Bears' matchup this week. Carlos Hyde has added an explosiveness to the 49ers' running game that simply hasn't been there in recent years. Frank Gore remains effective and continues to find space with his excellent vision and balance. And one would assume the 49ers will welcome back veritable road grader Alex Boone to the starting line-up after playing only four snaps in Week 1.

While I have no doubts that the 49ers will find success with the usual array of powers, traps, and whams against that Bears front, it could be a big day for the read option. We keep hearing about how the read option is dying now that defenses are more prepared to stop it, yet it continues to show up on Sundays. Chicago had problems defending Buffalo's zone read in the season opener, often overcommitting to either Fred Jackson on the give or E.J. Manuel on the keep. Jared Allen—frequently the player being read by Manuel—seemed especially indecisive and found himself out of position, unable to help against either the give or the keep.

On the play above, you can see Allen is hesitant to fully commit to crashing down the line of scrimmage towards Jackson despite having Shea McClellin on the outside to handle Manuel. The result is a nice hole up the middle and a gain of five for Jackson. Later in that same drive, Allen found himself out of position against a zone read play yet again.

After the snap, Lance Briggs immediately fills the strong-side A-gap, appearing to be responsible for Jackson on the give. Allen also is focused more on the give and slides down the line of scrimmage to cut off the cutback lane for Jackson. With the tight end sealing off safety Ryan Mundy to the outside, there's no one on the Bears' defense left to account for Manuel and he waltzes into the end zone for an easy score.

The 49ers had a good amount of success on read option plays in Week 1, especially with Hyde in the game. San Francisco's read option package is far more expansive that what Buffalo showed last week, not to mention the combination of Colin Kaepernick and Carlos Hyde poses a much larger threat than that of Manuel and Jackson. The read option is far from dead and if Chicago continues to have lapses like the ones shown above, we could see a lot of it on Sunday night.

Dealing with the loss of Bowman and Smith

The Bears are not the only team with concerns in the front of their defense. Though the issues are far less severe than the ones plaguing the Bears, the 49ers are figuring out how to compensate for the loss of NaVorro Bowman and Aldon Smith.

In a vacuum, it's easy for 49ers' fans to talk themselves into the absence of their two All-Pro linebackers not being that big of a deal. San Francisco has boasted one of the most talented rosters in the league for the past several seasons, with depth that few teams in the league are able to match. And when one of their stars has missed time, the 49ers have been able to plug in the next man up and maintain basically the same level of performance. Michael Wilhoite has played well filling in for an injured Patrick Willis on a few occasions, with the combination of Dan Skuta and Corey Lemonier doing the same during Aldon Smith’s five-game absence last season. However, dealing with the loss of two key players is a far more complicated matter.

Over the last several seasons, San Francisco has fielded one of the very best run defenses in football, success that has been heavily dependent on the play of their linebackers. The 49ers aren’t a team that gets a ton of penetration and blows up runs in the backfield. According to Football Outsiders’ data, the 49ers ranked 31st in stuffed percentage—runs that were stopped at or behind the line of scrimmage—last season, a ranking they matched in 2011. Instead of stopping runs before they get going, San Francisco forces teams into a never-ending stream of three-yard gains, rarely allowing backs to break into the open field for big gains. While the defensive line certainly plays a key role in occupying blockers, this style of run defense is dependent on the linebackers to make plays.

With the best linebacking corps in the NFL, making those plays has never been a problem. They’ve not only made life difficult for opposing running backs on a consistent basis, they’ve done so without the help of a safety dropped down in the box the way so many other teams do. Much of what the 49ers are able to do on defense is because of the outstanding play from their linebackers. Remove half of that group and the result is performances like the one we saw against the Cowboys.

DeMarco Murray had one of the best performances by any running back in Week 1, averaging 5.4 yards per carry on his way to 118 yards on the day. This was not a case of one big run inflating a day worth of three-yard carries either. Murray produced five or more yards on 12 of his 22 carries while accounting for eight first downs on the ground. Most teams are going to give up on the run when facing a 21-3 deficit at the end of 1st Quarter. It was telling that, even though the 49ers were without both of their starting cornerbacks for most of the game, Dallas felt their best way to move the ball and get back into the game was to hand the ball to Murray. If not for a few horrid decisions from Tony Romo, it just might’ve worked.

It doesn’t get much easier for San Francisco’s run defense in Week 2. The Bears’ offensive line is not of the same caliber as the Cowboys—especially if left guard Matt Slauson, who might have been Chicago’s best offensive lineman in 2013, is unable to go—but they’re an effective group. With the status of both Brandon Marshall and Alshon Jeffery in question, expect the Bears to lean heavily on Matt Forte, who is every bit as talented as Murray. If Jay Cutler can avoid the same fatal errors that doomed Romo—something that could be more likely than you would think if the Bears go with a more conservative game plan to compensate for the injuries to their star receivers—the 49ers are likely to find themselves in a much closer contest than a week ago.