The Chicago Bears finished 4th in the NFL in pass defense in 2015, which is a remarkable improvement after finishing 30th against the pass the previous season.
Yet that number is a bit misleading.
The Bears allowed 7.5 yards per pass attempt, which ranked 20th in the league, while their 62.9 completion percentage against was just 14th best. In addition, quarterbacks had a 99.2 QB rating against Chicago's defense, which ranked 26th, while their 31 passing TDs against ranked 25th and their 8 total interceptions were 30th.
The team gave up just 225 yards per game through the air, which is solid, but that was more the product of volume than superior secondary play. Due to a highly inconsistent run defense, opposing offenses attempted just 512 passes against the Bears, which was 4th fewest in the NFL.
With that in mind, let's evaluate the play of Chicago's cornerbacks from last year.
Kyle Fuller struggled mightily for most of his rookie season in 2014 and that carried over to the off-season this year, where he appeared to lack confidence and was routinely worked over by Alshon Jeffery in training camp.
His inconsistencies continued well into the regular season. Through the first seven weeks, opposing quarterbacks had a 137.8 QB rating when throwing at Fuller, who also gave up four touchdowns during that span.
Yet something happened during Chicago's bye week, from which Fuller emerged a much different player. Between Weeks 8-17, opposing quarterbacks had a 50.2 QB rating against Fuller, who gave up just one touchdown over the final 10 weeks. That is a remarkable turnaround.
At season's end, Fuller's QB rating against was a solid 86.9, second lowest among the team's full-time cornerbacks, and he led the defense with two interceptions. In 1,039 snaps, he was targeted 69 times, allowing 39 receptions. His 56.5 completion percentage against was also second lowest at his position, while his 9 pass breakups were second most on the team.
In run support, Fuller had a number of splash plays, as he's always been a willing and physical tackler. Yet he was inconsistent, missing 10 tackles, which was five more than any other cornerback on the team.
Porter played for John Fox in Denver in 2012, so it wasn't surprising when the Bears signed the eight-year veteran to a one-year deal last off-season. Injuries plagued Porter in two of his three previous years and he was again banged up for most of the preseaon, which forced him to sit out the club's first two regular season games.
By Week 4, Porter was inserted as the starter opposite Fuller. In his first eight games as the starter, he accumulated an impressive 10 pass breakups. He showed a knack for the football, using his veteran savvy to take pressure off Fuller, which was one of the big reasons for Fuller's second half turnaround.
Porter finished with a team-high 12 pass breakups, with one interception and one forced fumble, while his 52.6 completion percentage against was tops among Bears corners.
Yet Porter was very inconsistent in coverage, particularly down the stretch. For the season he gave up 7 TDs and 16.8 yards per completion, both of which were team highs.
McManis, who had never been a defensive starter in his career, emerged from camp as the club's No. 1 slot corner. That was a mistake, as he turned out to be a complete liability in coverage.
He was targeted 28 times on the season, allowing 21 receptions, five of which went for touchdowns. His 75.0 completion percentage and 147.6 QB rating against led all Bears corners.
McManis was eventually benched following the Week 7 bye but was inserted for eight plays the following week against the Vikings due to injury. In those eight snaps, he was called for a crucial pass interference penalty, then two plays later he allowed the game-winning score to Stefon Diggs.
Defensively, McManis showed very little, yet he was very valuable in the third phase and led the team with 17 special teams tackles - based on Bears coaches review. As a gunner in coverage, McManis is one of the best in the business.
The Bears gave Ball $3 million last off-season, believing the eight-year veteran could be a full-time starter. Like McManis, Ball failed to live up to expectations.
In three starts at the beginning of the regular season, he was targeted 17 times, allowing 13 receptions, two of which went for touchdowns. His 150.9 QB rating against over those three starts was one of the worst in the entire NFL. Ball was benched by Week 4 and served as the team's dimeback the remainder of the year, getting just 5-6 snaps per contest.
He finished the season with a 142.4 QB rating and 69.6 completion percentage against, second worst on the team behind only McManis.
Callahan, an undrafted rookie out of Rice, was one of the biggest surprises for the Bears this season. He made the 53-man roster coming out of training camp but was sent down to the practice squad in Week 3, before being called up during the Week 7 bye to replace McManis as the team's starting nickelback.
In 329 snaps, Callahan was targeted 33 times, allowing 20 receptions. He did not give up a single touchdown all year, while his 79.0 QB rating against was lowest among Bears corners.
Hurst was Chicago's starting cornerback his rookie season in 2014 but was converted to safety during training camp. He was active the first week of the season but was then cut the following week. In Week 3, he was signed to the practice squad. He was then elevated to the active roster for two weeks before being sent back down to the practice squad for the next six weeks.
Hurst was called back up to the active roster in Week 14 and started at nickelback in Weeks 15-16 while Callahan was hurt. He was only targeted twice during those two starts, so he didn't see much action, but Hurst proved to be one of the more versatile defenders on Chicago's roster.
The Bears are obviously going to keep trotting out Fuller, the team's 2014 first-round pick, as a starter, and he deserves it. He showed exceptional improvement as the season went on, displaying good ball skills and anticipation. Secondary coach Ed Donatell deserves a lot of credit for Fuller's turnaround.
He's very talented but for more than a year, he couldn't overcome a crippling mental hurdle. Once he did, Fuller emerged as viable No. 1 cornerback. If he continues to improve under Donatell and coordinator Vic Fangio, Fuller will be a staple of Chicago's defense for years to come.
Porter was a pleasant suprise this year but he faded down the stretch, and injuries will always be a concern with him. There are definitely worse options than Porter going forward but he'll be 30 by the start of next season, so he's by no means a long-term option.
Callahan showed some playmaking ability this year and was the most consistent cornerback on the team. He deserves another opportunity to compete for Chicago's starting nickelback role next season.
At the end of the day, the Bears need upgrades at cornerback. Fuller is still a long-term option but it's dangerous to rely on Porter and Callahan for 2016 and beyond. Another quality shut-down corner would do wonders for Chicago's defense, and would allow Fangio to use more press coverage, giving him the flexibility to be more creative in his blitz packages up front.
Don't be surprised if GM Ryan Pace addresses the cornerback position in the first three rounds of this year's draft.