In the span of a few short weeks, Marcus Cooper has regressed from Defensive Rookie of the Year candidate to spurned castaway on an increasingly lonely island.
But while Cooper has taken the brunt of the blame, the Chiefs secondary as a whole has looked like a shell of its former self.
Throughout the first nine weeks, Kansas City's defensive backs served as the benefactors of two things: subpar quarterbacking (with a few exceptions) and a smothering pass rush rush that, at one point, was blazing a historic pace.
Don't get me wrong: The Chiefs' defensive dominance throughout the first half of the season was far from a fluke. However, offenses have slowly but surely solved the riddle.
What's Wrong with Cooper and Company?
First of all, let's state the obvious: Justin Houston's injury handcuffs the defense. There's a reason why Eric Decker looked like the second coming of Randy Moss while Wes Welker was an afterthought last Sunday.
For starters, Denver knew that after the rivals' first matchup, Kansas City's main priority would lie in defending picks and underneath routes. The most effective way to counter that? Double moves and vertical routes, which are infinitely easier to execute with a sidelined Houston and gimpy Tamba Hali.
Kansas City's defense is predicated on rushing the passer. When that element's negated, the Chiefs become spectacularly average, and defensive coordinator Bob Sutton hasn't helped the cause.
Brandon Flowers is the only cornerback whose game doesn't include a glaring weakness.
Sean Smith? One of the better bump-and-run defenders in the league. However, if quicker receivers survive his initial jam and gain a step, he doesn't tote the necessary speed to bridge the gap.
Dunta Robinson? He's a 31-year-old backup with a documented history of knee problems. Robinson is an instinctive, mercilessly physical corner who excels in zone, but his deteriorating speed and agility make him a less-than-ideal fit for Kansas City's man-centric scheme.
As for Cooper? His deficiencies are so elementary that they're borderline alarming, but they're also correctable.
If he doesn't give up inside leverage, Cooper is adequate in press-man when guarding receivers similar to his stature or smaller.
However, when he's asked to jam physical receivers, he tends to be rag-dolled on a regular basis. Like most rookies, Cooper's technique sporadically veers away from fundamentals, which veteran receivers exploit with relative ease. To compound the issue, he simply doesn't embody the strength to fend off larger opponents.
Here, Cooper's matched up with Demaryius Thomas while Smith squares off with Decker. Smith bumps his man with a solid jab and closely shadows Decker's inside foot throughout the route.
Cooper, meanwhile, remains planted in his original position after the snap. That subtle mistake results in the rookie's momentum shifting to the outside with off-balanced hips. Thomas simply swipes Cooper's inside shoulder and turns him around, making for an effortless 14-yard gain.
Later, sloppy fundamentals lead to the first-year corner being dusted for a near-touchdown. Before the ball is snapped, Cooper's feet are pointed outward (as opposed to square with his shoulders), which is setting himself up for failure in press-man.
Due to this, his hips are too wide (virtually) from the moment that Manning snaps the ball, again causing him to lose his balance. Like Thomas, Decker easily exploits Cooper's momentum to his advantage and torches No. 31 (who was flagged) for a touchdown.
Cooper's far from the only problem, though. The safeties, particularly Kendrick Lewis, often commit to mind-boggling angles and/or fail to close distance in an adequate amount of time. Also, in an effort to thwart the underneath game, Sutton has become infatuated with hi-lo safety concepts, which regularly leave one of the corners on an island.
The good news?
Kansas City is scheduled to face Robert Griffin III.
How the Chiefs Can Take Advantage of RGIII
Washington's second-year sensation oozes with talent, but at this point in his career, he's often too confident for his own good.
Sutton, the Chiefs' defensive architect, regularly tries to disguise his defensive intentions. Nine times out of 10, that will backfire against veterans like Manning and Rivers, especially if the pass rush is M.I.A. However, his approach tends to be more effective against inexperienced passers, and Griffin has proven that he's no exception to the rule.
With the exception of Trent Williams, who is arguably playing better than any tackle in the NFL, Washington's pass protection is lackluster, to say the least. This, combined with Griffin's supreme confidence, often paves the way for hasty decisions and easy turnovers.
In this example, Griffin executes a play-action rollout, only to whip around to Aldon Smith breathing down his neck. Because of this, he hurriedly passes it to a receiver running a skinny post. The wideout, knowing that he's draped with defenders and trying to find a soft spot in the zone, doesn't even bother looking back for the ball, and San Francisco's strong safety snatches the easiest interception of his career.
In Week 8, Denver morphed into Cover 1 just before the snap, as Griffin (again under pressure) heaved the rock between the hash marks, despite having one-on-one matchups on the outside. Predictably, the Broncos notch another turnover.
Finally, during Week 7 at Chicago, the Bears show Cover 1, which leads Griffin to assume that the corners are playing man coverage. However, Charles Tillman, knowing that he has deep help, releases from his initial target and jumps the deep cross.
Kansas City's secondary should fare far better than it has in weeks past. Even without Houston, the pass rush should become more prevalent and, unlike Denver's wideouts, Washington's receivers aren't going to impose their will on Cooper at the line of scrimmage.
Griffin has only completed 11 of his 44 attempts that have traveled 20-plus yards through the air. As long as the safeties keep everything in front of them, Kansas City's secondary should have plenty of opportunities to turn the tide of momentum and recapture its swagger from the first half of 2013.
Statistics provided by Pro Football Focus (subscription required).
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