No position in football has seen such sweeping, job-responsibility changes over the past decade than linebacker.

We're celebrating 100 years of NFL football this season and for about 90 of those years, a linebacker's main objective, his most critical task, was to stop the run.

Whether it was flying downhill or ranging toward the sideline to lay the lumber, that duty made linebackers ferocious characters, easily recognizable guardians of yardage with broad shoulders, thick legs, and nasty demeanors.

Now, coverage is most vital. It's not as flashy as the old, main job responsibility of the position, and strength is not nearly as much of prerequisite than it was. Plenty of linebackers can still authoritatively fill running lanes, dispatch blocks, and beat running backs to the corner. Only a small collection flourish in coverage. And there's simply not as many linebackers on the field as their used to be, thereby making those on the field more valuable.

Per Football Outsiders, NFL teams only used a "base" formation -- with three linebackers -- on 25% of snaps in 2018. Either one or two defensive backs played in place of linebackers 73.8% of the time. Also, the league-wide passing rate was 57.1%. It's currently 57.9%.

Therefore, as an analyst, I'm caring less about a defender's run defense and caring more about how a defender impacts pass plays.

Different sizes, same specialty

Edmunds is 6'4-1/2" and 253 pounds. He ran 4.53 at the combine. He was picked in the first round by the Bills in 2018 after his true junior season at Virginia Tech and famously played his entire rookie season as a 20 year old. Milano is 6-0 and 223 pounds. He ran 4.67. He was picked in the fifth round (of the 2017 Draft) after his senior year at Boston College and was 23 his entire rookie season.

Despite their vastly different physical appearances and paths to Buffalo's roster, Edmunds and Milano are coverage masters at the linebacker position. I thought this tweet on Edmunds and Milano was perfect.

Edmunds flashed but unsurprisingly experienced growing pains in his rookie campaign. Beating blocks against the run was the weakest part of his game, followed by the speed at which he diagnosed plays. However, he quietly finished second among all linebackers with 12 pass breakups, a stat aided by his enormous 83" wingspan, one of the widest at the position at the combine in at least the past 20 years.

Milano had seven pass breakups and intercepted three passes in 13 games last year.

Going next level, here's how they fared in 2018 in three telling coverage statistics: completion percentage allowed, yards per target, and yards after the catch per reception allowed.

Comp % Allowed (Rank) Yards Per Target YAC Per Reception Allowed Tremaine Edmunds 78.5% (50th) 6.8 (T34th) 5.64 (23rd) Matt Milano 56.5% (2nd) 6.20 (19th) 7.76 (59th) NFL linebacker average in '18 72.0% 6.64 5.82

Solid figures across the board, and Milano fared better overall. Yes, the Bills -- and many other teams -- play a good amount of zone coverage, which would obviously inflate the defenders' completion percentage allowed figure.

However, Edmunds and Milano together disrupted 24 passes (19 passes and snagged five picks) the top totals for a linebacker duo, as the Rams finished second at 18 such plays. Despite the stellar ball production, Buffalo's pairing was somewhat susceptible through the air.

But so far in 2019, Edmunds and Milano have gotten stingier. The sample size needs to be considered, of course, but they've started impressively in their second year together.

Comp % Allowed (Rank) Yards Per Target YAC Per Reception Allowed Tremaine Edmunds 52.6% (2nd) 3.4 (4th) 3.3 (8th) Matt Milano 68.4% (18th) 4.9 (11th) 3.0 (3rd) NFL linebacker average ('19) 74.4% 6.40 4.92

And it's not just individual play of Edmunds and Milano. The defensive scheme set forth by head coach Sean McDermott and defensive coordinator Leslie Frazier dazzled and done an excellent job limiting big plays. Buffalo has surrendered 46 pass plays of 20-plus yards since the start of 2018, the fewest "explosive" plays allowed in that time frame in the NFL. Chicago is in second at 52.

Also, the Bills have gone 14-straight games without allowing more than 250 yards passing, currently the longest such streak in football.

Beyond that, Buffalo has hindered opposition's mismatch opportunities.

As a team last season, the Bills finished seventh in yards per target allowed to running backs -- primarily covered by linebackers -- at 5.54. Against tight ends, the other "mismatch" position against linebackers, Buffalo allowed just 5.88 yards per target, the lowest figure in the league. The Bills are actually in 21st at 7.94 yards per target against tight ends at this stage in 2019, but only two teams have surrendered fewer catches (13) to that position and just three teams have given up fewer yards (151).

Against running backs through Week 5 this year, the Bills defense has allowed 5.11 yards per target to running backs, the seventh-lowest number in football.

And while the likes of safeties Micah Hyde and Jordan Poyer, and a deep defensive line anchored by edge rusher Jerry Hughes, penetrating nose tackle Jordan Phillips, and first-rounders Shaq Lawson and Ed Oliver, the Bills' young linebackers are blossoming into coverage superstars, which significantly boosts the production and overall potential of the Buffalo defense.