David Amerson's 2014 and the Worst Cornerback Seasons of the PFF Era

The 2014 Washington Redskins had one of the worst passing defenses in the 83-year history of the franchise.  However, just saying that doesn't adequately articulate just how horrendous this team was in pass coverage.  That simply wouldn't be doing them justice, because they also rank among some of the worst pass defenses in NFL history.

2014 Pass Defense	Redskins 2014 Value	Franchise All-Time Rank	NFL All-Time Rank
Completions Allowed	345	4th Worst	132nd Worst
Pass Yards Allowed	3,990	3rd Worst	63rd Worst
Pass TD Allowed	35	2nd Worst	10th Worst
PFF Pass Cov. (since 2007)	-79.2	Worst	Worst
Pass DVOA (since 1989)	29.5%	2nd Worst	32nd Worst

These are team statistics and records and no one person should bear all of the blame for them.  However, if we must single out one individual, then there is nobody more responsible for these results than David Amerson.  Amerson's 67 receptions, 877 receiving yards and 10 receiving touchdowns allowed were all the most given up by any player on the team, and they accounted for 19%, 22% and 29% respectively of the total amounts allowed by the team as a whole.

Futility Quantified

After looking at those numbers several times I started to get an inkling that his 2014 season might be even worse than I initially thought, so I decided to dig deeper.  I used Pro Football Focus' advanced game charting stats and grading to look back to see where Amerson's 2014 season ranks among the worst seasons by a starting corner on record.

Unfortunately, their data only dates back to 2007; however, that should be a more than adequate sample size.  Especially, when you consider that if we went back much further that era adjustments would probably be required to make a fair comparison.

It should also be noted that PFF player seasons are based on what team the individual played for, so if a player is traded or released and signs with another team midway through the season then those results are separated.  I did not combine those numbers, but based on what I observed I don't believe that this will have much of, if any, effect on these rankings.

Also, we will not be going over PFF run defense grading in depth here.  We are looking at cornerbacks and I want to focus on their primary job  or function of covering offensive players on passing plays.  Their overall PFF grade does, however, incorporate the player's run defense grade.

There were over 1,500 player seasons by cornerbacks to compare to David Amerson's 2014 campaign to.  Here is how Amerson stacks up against them in a few of the more basic statistics and PFF's ratings.

Pass Defense Allowed	Rec Allowed	Yards Allowed	TDs Allowed	PFF Overall	PFF Coverage
David Amerson 2014 Values	67	877	10	-20.2	-15.5
David Amerson 2014 Rankings	30th Worst	30th Worst	Worst	4th Worst	7th Worst

When I saw these numbers, I began to realize that Amerson's 2014 may indeed be one of the worst cornerback seasons in recent memory - and in recorded history for that matter, because I don't think we can adequately compare DB seasons without PFF's game-charting data.  Before we can move on with this analysis and prove that theory, we need to pare things down.

Separating Out the Starters

In order to fairly judge Amerson's efficiency rankings, we must first trim some of the fat off of our group of 1,500-plus cornerbacks.  The reason being, that it would not be equitable for us to compare Amerson to a corner that allowed an 80-yard TD pass on one of his just five snaps on the season or a corner who was perfect on just 10 coverage snaps.

My aim here was to include virtually every starting corner since 2007 in this new group along with a handful of other major contributors.  To figure out the right cutoff point, I looked at the coverage snap percentages for each year that PFF has game charting data for.  I noticed that every corner that had played at least 50% of their team's coverage snaps in a season had been in on no less than 320 such snaps.

To be safe and to make sure that we get an adequate amount of players in the sample I dropped the cutoff to 300 coverage snaps.  This should ensure that every primary starting corner and the majority of the most active slot and backup corners would also be included.  The new list consists of 628 player seasons.  All of Amerson's aforementioned rankings remained the same, but now we can see where he stands in terms of efficiency

Pass Defense Efficiency	Catch %	QB Rating	Yards/Cov Snap	Cov Snap/Rec
David Amerson 2014 Values	73.6%	140.2	1.73	7.6
David Amerson 2014 Rankings	22nd Worst	2nd Worst	34th Worst	48th Worst

Things look a bit better for the Redskin's young corner here, but these are also not the results that you want to see either.  At this point there was still no clear "worst" cornerback season, so I decided to cut things down one more time in a last-ditch effort to find the answer.

Bottom of the Backfield Barrel

I wanted to compare the worst of the worst here, so that's just what I got.  I took the lowest five ranked corners from the receptions, receiving yards, catch percentage, QB rating and overal PFF rating categories along with the ten lowest ranked corners in PFF coverage grade, receptions per coverage snap and yards per coverage snap categories (I valued the latter group more hence the higher number).

Dre Bly's 2007 season was also included because it was the only other time since that same year that a corner has allowed 10 receiving touchdowns.

This left me with 44 player seasons including: David Amerson's 2014, E.J. Biggers 2014 and DeAngelo Hall's 2012.  Bigger was the only player to make the list twice (with Tampa Bay in 2011).

I ranked the player seasons in the group under each of the aforementioned statistical categories to come up with an average ranking for each of them.  Here is where Amerson stands.

Categories	Amerson's Group Ranks
Rec Allowed	36th
Yards Allowed	33rd
TDs Allowed	43rd
Catch %	37th
QB Rating	43rd
PFF Coverage	38th
PFF Overall	41st
Cov Snap/Rec	24th
Yards/Cov Snap	26th
Average Rank	35.7

Amerson's average ranking of 35.7 was dead last in the group.  Only Chris Houston's 2007 season with the Falcons came close.  Does this mean that David Amerson had the worst season by any cornerback in at least the last eight years?

In an effort to double check myself one more time, I cut out some of the potential double counting done with the average rankings by removing receptions, yards, touchdowns and catch percentage from the equation. That leaves us with just five of the best and most efficiency-focused metrics.

That actually did change things as Houston now passes Amerson for the worst season.  Clearly the worst cornerback season in the last decade belongs to one of these two men.

The Futility Finals

Name	Year	Team	Snaps	Overall	Rush	Cov.	Run	Pen.
David Amerson	2014	WAS	926	-20.2	-0.1	-15.5	-4	-0.6
Chris Houston	2007	ATL	675	-9.1	0	-7.4	-0.5	-1.2

Name	Cov Snaps	TA	Rec	% Ct	Yds	Avg	TD	INT	PD
David Amerson	508	91	67	73.6	877	13.1	10	0	4
Chris Houston	375	86	58	67.4	793	13.7	7	0	8

Name	NFL Rating	Cover Snaps / Target	Yards / Cover Snap	Cover Snaps / Rec
David Amerson	140.2	5.6	1.73	7.6
Chris Houston	123.8	4.4	2.11	6.5

Amerson, like Houston, made absolutely no plays.  In fact, he is one of just 16 corners since 2007 to start over 12 games and not record a single interception, sack or force fumbled.  Amerson also failed to notch a QB pressure of any kind on the year.

If you want to make a case for his season being the worst, then I surely will not argue with you, but I have to go with Houston's 2007 atrocity.  He was worse in all of the per-snap measures, and I believe that he would have allowed more passing production had he been in on as many snaps as Amerson was.

Bottom Line

Ultimately, there are no winners here.  Just scroll down the list of the "Worst Seasons" table and you'll see mediocre corner after mediocre corner.  This certainly does not bode well for Amerson's prospects of going on to have an above-average NFL career.

We simply cannot expect anything from David Amerson going forward; nor should we not after such a historically disastrous season like the one he just had.  Scot McCloughan knows this and it's a big part of the reason why he paid top dollar to bring in the more dependable Chris Culliver.

Culliver's addition may cause many fans to adopt the misguided belief that the Washington Redskins are set at the cornerback position.  However, McCloughan knows better than that, so don't be surprised if he chooses to bolster this unit with more reinforcements on the second or third day of the upcoming draft.