For the past two seasons, the Buffalo Bills have ranked in the Top 10 in the NFL in team defense (reaching No. 4 overall in 2014), paced chiefly by their excellent pass defense. While the run defense has been mired with inconsistency - though it's clearly much better than it was in previous seasons - the pass defense has been among the top handful of units in the NFL, ranking No. 4 overall in 2013, and No. 3 last year, allowing just 20 yards per game more than the Seattle Seahawks and their vaunted "Legion of Boom" secondary.
Naturally, the fact that the Bills boast one of the league's best pass rushes - they lead the league in the past two seasons combined with 111 sacks - is a big factor in the team's success defending the pass. But make no mistake about it, Buffalo's secondary is a major component to that success as well, and is coming off of an excellent 2014 campaign. There are concerns with the team's group of cornerbacks, durability chief among them, but this is a strong collection of talent nonetheless.
- Age: 24 (25 on September 19)
- 2015 cap #: $3.3M
- 2014 snaps: 838 (77.1 percent of total)
Durability has been a point of frustration for Gilmore over the past two seasons. Many felt that he was on the cusp of stardom after his rookie season concluded, but a wrist injury cost him five games in 2013, and then more minor injuries cost him two more last season. Still, Gilmore is easily coming off of his best year as a pro; he was more consistent than he'd been in his first two seasons, and was not thrown at nearly as often as he had been. Back in the Rex Ryan style defense, the highly physical Gilmore, who excels in press coverage, may be relied upon to play on an island and cover an opponent's top receiver on a weekly basis. Assuming he can stay healthy, Gilmore is up to the challenge.
- Age: 29 (30 on September 4)
- 2015 cap #: $4.9M ($2.9M savings if released)
- 2014 snaps: 534 (49.1 percent)
Now an eight-year NFL veteran that has spent his entire career with the Bills, McKelvin was enjoying one of the better seasons of his career - he'd accumulated four interceptions, a forced fumble, and eight defended passes in 10 games - before a knee injury brought a premature end to his season. McKelvin is, arguably, the Bills' best defender when it comes to defending the deep pass, and while he isn't the type that can anchor a secondary, he can certainly thrive when the talent around him is high-caliber. Assuming full health, McKelvin has an inside track on a starting gig heading into the 2015 season.
- Age: 29 (30 on July 25)
- 2015 cap #: $4.3M ($1.3M savings if released)
- 2014 snaps: 778 (71.6 percent)
Acting as the utility infielder of the Bills' secondary in 2014 - he spent most of his time at corner, but took a healthy number of reps back at safety, as well - Graham was excellent. He was the most consistent defensive back on the team, and the glue that held the unit together through injuries. There are some limitations to his game - namely, his ability to turn and run on the perimeter - but overall, Graham is a seasoned and dependable player that, no matter his position, will remain an invaluable member of Buffalo's secondary in 2015. Don't be surprised, however, if the Bills' new defensive coaches, highly reliant on man coverage, consider Graham a better fit at safety.
- Age: 23
- 2015 cap #: $587K
- 2014 snaps: 640 (58.9 percent)
One of the Bills' most pleasant surprises as a rookie in 2013, Robey regressed in his second season playing in a more traditional defensive system that did not take advantage of his unique strengths. Robey is a small, quick-footed slot cornerback capable of mirroring the game's fastest slot receivers, but he loses utility the further away from the line of scrimmage he gets. Playing under Ryan and Dennis Thurman, Robey will almost certainly return to the blitz-happy ways of his productive rookie season, and it's fair to expect him to re-emerge as one of the better slot corners in the business.
- Age: 26 (27 on October 16)
- 2015 cap #: $670K
- 2014 snaps: 145 (13.3 percent)
Brooks is little-used as a cornerback, and only saw the field in limited spot duty in 2014 when players were injured in front of him. But he's worth keeping in the back of your mind - not because of how he capably filled in during that limited playing time last season, but because he emerged as one of the team's best special teams players. He finished fourth on the team in special teams snaps played despite missing two games due to injury, and figures to be a big part of Danny Crossman's coverage unit plans heading into the 2015 season.
2014 fourth-round draft pick Ross Cockrell was basically redshirted as a rookie, but still has a nice size-length-speed combination as the top prospect in the defensive backfield. He could push for playing time this season. The Bills also retained two corners on reserve/future deals: Rod Sweeting, who spent the last part of the season on the practice squad, and Jonte Green, who was added after the season. Mario Butler is also still with the team after spending the 2014 season on injured reserve.
Whether or not the Bills feel the need to address the cornerback position will hinge, to an extent, on how they classify Graham in a more aggressive, man-oriented coverage scheme. Graham is better when the play is in front of him, which could mean that he'd be more useful playing as a safety. But even if the Bills do wind up making that decision, Graham is still an option on the perimeter, and Cockrell is talented enough to pick up the slack in a limited role (or fill in for injured starters). The Bills are in pretty good shape at this position, which is not an easy feat to accomplish in today's NFL.