Pro Football Focus loves Adrian Amos, but what does that mean?

Say what you want about Pro Football Focus, you can't deny they have successful engrained themselves and their analytic tentacles deeply into the football world. Even if their majority shareholder—Chris Collinsworth—wasn't one of the most successful television color commenters on the business, you wouldn't be able to shake a stick at a major football media outlet without whacking into a PFF grade or signature stat.

Given their prevalence, most fans have come across a PFF grade or opinion that rubbed them the wrong way. For your average fan base, this usually occurs when a favorite player gets a surprisingly low grade.

But this is the Bears. We're Bears fans. And we are very (and let's face it, appropriately) skeptical of anything good.

So last offseason, when PFF labeled Adrian Amos the Bears' secret superstar, we shrugged it off. When they placed him as a first teamer on their mid-season all pro team with a grade just below that of frequent-Bears-terrorizer Harrison Smith, nobody noticed. Which is fair. Who makes a mid-season all pro team, anyway?

But when PFF named Adrian Amos one of the biggest Pro Bowl snubs—saying he should have replaced Landon Collins—and placed them on their actual end-of-season all pro team, it finally caught my attention.

Why is it that most Bears fans, including myself, have thought of Amos as "fine" to "good," but a begrudgingly-respected analytics team that watches every player on every snap keeps ranking him among the elite?

The Player

Adrian Amos is a consistent and reliable player who is almost always in the right place in pass coverage. He doesn't always make a play on the ball, but he's always right there and he's a sure tackler who doesn't let the receiver get anywhere after the ball is caught.

In run defense, Amos is aggressive without being reckless. He has a good combination of instincts and discipline that allow him to make safe stops a yard or two earlier than expected.

He's not a frequent big-play flasher, and he doesn't make big mistakes. This combination means he will go unnoticed to anyone who's not intently focusing on him. Many have argued that this is a good thing. A safety that isn't getting noticed is probably doing their job and doing it well.

The Grading System

Pro Football Focus isn't 100% transparent about their grading system, but there is a lot that they have shared with the public. The basic method is that a player is graded on every snap on a -2 to +2 scale, with grades given in half point increments. Those per-snap grades are combined to make an overall game grade for each game, which is normalized to a 100 point scale where 70 represents an average player. The specific math here is not explicit, but presumably it's similar to grading on a curve.

It's unclear how regimented the scoring system is, but there is certainly an amount of subjectivity to these evaluations. On PFF's recent article about their quarterback evaluations, it looks like they are describing every pass graded between 1 and 2 as a "big time throw," every pass graded between -1 and -2 as a "turnover-worthy throw" and those in between as "common or expected throws." This suggests there are labels/guidelines for what type of play earns each score. It also suggests a play needs to be significantly good or bad to score a score of + or - 1.

When discussing their scoring, PFF is explicit about a few things. First, they want to isolate the individual player as much as possible, grading the play on what that player does independent of what other players do or even the outcome of the play. If Amos tips a pass that Eddie Jackson catches and returns for a touchdown, it should be graded the same as a play where Amos tips a pass that an offensive player ultimately catches.

Second, they do not adjust for level of competition. If Adrian Amos plays well against Brett Huntley, it counts just as much as if he plays well against Drew Brees. This policy can lead to some questionable single game grades (Mitchell Trubisky had the highest grade of any quarterback the week he played the catnapping Bengals) but PFF argues that it will even out over the season. In contrast, Football Outsiders does adjust for competition. Both choices have limitations, and I discussed how this adjustment likely biased Football Outsider's grade on Markus Wheaton when I wrote a number plunge about him last summer.

If PFF requires quarterbacks to make a "big time throw" to score +1 or more, I would guess a safety needs a tackle for loss or a pass breakup to get a similar score. You would think getting a forced fumble or interception might get him a +2. Then, of course, an interception returned for a touchdown would also get him a +2, and a strip sack picked up for a touchdown in a tie game with 0 seconds on the clock would also get him a +2. And intercepting the ball before throwing it into the crowd to disarm the sniper rifle from the grip of a French assassin, saving his quarterback's life and averting a series of events which would ultimate have led to a third world war would also earn him—you guessed it—a +2.

As I mentioned above, Adrian Amos looks like a "good" player when you watch him. If I were grading him, most plays I would say he did a little better than expected and give him a +0.5, the smallest positive grade available in the PFF system. If Wonder Woman were a safety, she could save the world every 4 plays and she still wouldn't be able to outpace Amos if she plays average on the other three while he consistently earns himself a shrug and a +0.5.

That, I believe, gets to the meat of the reason PFF's system grades players like Adrian Amos so highly. The best possible play is only valued at 4 times as good as the least impressive positively-graded play. Whether you call it a lack of granularity, nuance, or resolution in their grading system, it's a limitation that will always favor a consistently above-average player over a consistently average player who occasionally—or even frequently—makes exceptional plays.

The Verdict

Adrian Amos is a great safety. He frequently gets stops in crucial moments, and he rarely makes mistakes. As the name implies, the most important role of a "safety" is preventing the defense from give up big plays, and Amos does exactly that. Good Bear.

Is Adrian Amos the second best safety in the NFL as PFF's grading system suggests? Unfortunately, no. I'm still glad to see him balling out in navy and orange every week.