Associated Press

Change is never easy in the NFL, and the Chicago Bears are learning that this season.

The Bears were famous in the 1980s for their 46 defense, and they went to a Super Bowl after the 2006 season while running Lovie Smith's Cover 2 defense, but the team installed a 3-4 defense this offseason for the first time under new defensive coordinator Vic Fangio.

Chicago is currently sitting with an 0-3 record, but the defense is steadily improving under Fangio.

Chicago's defense dominated at times under Smith, and to keep continuity on that side of the football, the Bears opted to run a version of Smith's Cover 2 with new coordinator Mel Tucker after the team fired Smith following the 2012 season.

During Tucker's two years with the Bears, the organization had two of its worst defensive seasons in team history.

Chicago's Defense Under Mel Tucker Year Points/Game (NFL Rank) Yards/Game (NFL Rank) Rushing Yards/Game (NFL Rank) Passing Yards/Game (NFL Rank) 2013 29.9 (31st) 394.6 (30th) 161.4 (32nd) 233.1 (18th) 2014 27.6 (31st) 377.1 (30th) 112.7 (17th) 264.4 (30th) NFL.com

Tucker—along with the rest of former head coach Marc Trestman's coaching staff—was shown the door following the 2014 season. Chicago's roster was filled with players who were good fits in a 4-3 defense, and many were forced to move to new positions this offseason.

Defensive ends Lamarr Houston and Willie Young moved to outside linebacker, outside linebackers Shea McClellin and Christian Jones moved to inside linebacker, nose tackle Ego Ferguson moved to defensive end and 3-technique defensive tackle Will Sutton moved to the 0-technique nose tackle position.

In addition to those six, Jared Allen also moved to outside linebacker after spending his entire career as a 4-3 defensive end. Allen started at outside linebacker in Chicago's first three games of the season, but the team traded him to the Carolina Panthers earlier this week.

Allen struggled to put pressure on opposing quarterbacks, and head coach John Fox told WBBM Newsradio 780 and 105.9 FM on Monday he thought the trade was a good move for both the team and Allen, via Kevin Fishbain of ChicagoFootball.com:

I think it’s a win-win for both sides. Jared’s done everything we’ve asked. He was all in as far as learning outside linebacker. Truth be told, his experience in a very, very good career has been with his hand in the dirt in the 4-3 and this was an opportunity for us to get a sixth-round draft pick as well as give him an opportunity to go finish his career as a defensive end.

The former All-Pro defensive end struggled at his new position, but many players on the roster have been showing steady improvement since Week 1.

After giving up an average of 377.1 yards per game last season, the Bears are allowing 331 yards per game this season—11th best in the NFL. The team's run defense is still suspect, but the pass defense has held up well considering it went up against Green Bay's Aaron Rodgers, Arizona's Carson Palmer and Seattle's Russell Wilson in the first three games of the season.

Chicago's Defensive Stats Through Week 3 Total Yards/Game (NFL Rank) Rushing Yards/Game (NFL Rank) Passing Yards/Game (Rank) 331.0 (11th) 135.7 (Tied for 28th) 195.3 (6th) NFL.com

Chicago has given up the second-most passing touchdowns this season with eight, but the defense held Rodgers to 189 yards passing, Palmer to 185 and Wilson to 235. Giving up eight passing touchdowns in three games is not ideal, but Chicago's defense started to show some life last week against Seattle.

Before the start of last week's game, the Bears had not recorded a sack. The Bears were able to apply pressure at times to Rodgers and Palmer in Weeks 1 and 2, but they were able to take Wilson down four times this past Sunday.

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Defensive end Jarvis Jenkins and outside linebacker Pernell McPhee both registered two sacks apiece in Week 3. The Bears spent all of the offseason, training camp and preseason trying to find a new identity on defense, and McPhee thought some of that started to come through against the Seahawks last Sunday.

"You could see in some of them plays we were playing with an attitude, we were playing with a swag," McPhee said, per Dan Wiederer of the Chicago Tribune. "And all that goes to show that it’s coming along. The defense is starting to play together.”

Both Jenkins and McPhee applied constant pressure on Wilson all afternoon in Seattle, and McPhee is quietly becoming one of the league's best at applying pressure, according to Pro Football Focus:

Since the Bears were able to apply pressure against Wilson last week, Chicago's struggling secondary was able to hold its own against Seattle's wide receivers. Cornerbacks Kyle Fuller and Alan Ball struggled against Green Bay and Arizona, but both showed improvement last week.

According to Pro Football Focus, Fuller was targeted four times in the passing game against Green Bay in Week 1, and he allowed two catches for 42 yards. Ball was targeted five times on the day and allowed four catches for 51 yards and two touchdowns.

In Week 2 against the Cardinals, Fuller was targeted four times in the passing game, and he allowed three catches for 60 yards with two touchdowns, per Pro Football Focus. In addition to giving up two touchdowns, Fuller was also flagged for a 42-yard pass interference penalty. Ball was targeted four times, and he allowed three catches for 35 yards. He was also called for a 38-yard pass interference penalty.

According to Pro Football Focus, the Seahawks targeted Ball eight times in pass coverage in Week 3, and he gave up six catches for 101 yards. Despite giving up a big number of catches and yards, Ball had two nice plays in the end zone at the end of the first half to prevent Seattle from scoring. Fuller was only targeted twice, and he allowed one catch for four yards.

Troy Wayrynen-USA TODAY Sports

It was a bit surprising that the Seahawks stayed away from Fuller throughout the afternoon despite his struggles in the first two weeks, but he played with solid technique throughout the game.

Starting safeties Antrel Rolle and Adrian Amos have both done a nice job against the run this season, but they are going to need to start making plays in the passing game. Jones and McClellin have flashed at times at inside linebacker, but they need to show improvement against both the pass and the run.

Chicago's defense showed in Week 3 it can compete against a top-level offense like Seattle's, but it will need to continue to put constant pressure on opposing quarterbacks in the weeks to come. With Allen now in Carolina, Houston and Young will get more opportunities to rush the quarterback, but veteran Sam Acho is expected to start in Allen's place, per the Chicago Sun-Times' Adam Jahns:

Fangio later explained why Acho will get the start opposite of McPhee this week against the Oakland Raiders.

“Well, he’s had the most experience playing in this type of defense,” Fangio said, per Jahns. “So he has picked it up fast and is very comfortable in what we are doing and is very knowledgeable and does a solid job when he is out there.”

On Sunday, the Bears will face the difficult task of trying to sack Raiders quarterback Derek Carr. Oakland's offensive line has given up just three sacks this season. Carr was sacked just once, while backup Matt McGloin was sacked twice.

Oakland sits with a 2-1 record, and the Raiders have been led by their potent offensive attack the last two weeks. Carr threw for 300-plus yards in back-to-back wins over the Baltimore Ravens and Cleveland Browns the last two weeks, and he has a talented weapon in the passing game in rookie wide receiver Amari Cooper and a talented running back in Latavius Murray.

"They're an explosive offense," Houston said when asked about the Raiders, per Larry Mayer of ChicagoBears.com. "They have three great young players who are carrying the offense right now, and they're winning ballgames. It's a different team than when I was there. You've got to tip your hat to them."

The Bears are not at an elite level on defense like they once were back in the 1980s or in the mid-2000s, but the unit looks much better through the first three weeks of this season than it did at any point during Tucker's tenure as defensive coordinator.

Chicago's defense still has a long ways to go and will face a difficult matchup this weekend against Oakland, but the unit appears to be heading in the right direction under Fangio.

Statistical information courtesy of NFL.com unless otherwise noted.



Matt Eurich is a Chicago Bears featured columnist for Bleacher Report and a member of the Pro Football Writers of America.

Follow @MattEurich.