We watched every Sean Smith snap from last season ... so how much is he worth?

Sean Smith is currently the subject of a lot of debate among Chiefs fans. Should Chiefs GM John Dorsey pay to keep the free agent corner, who has been a big part of the defense the last few years? If so, how much is too much?

As always, sides have been taken, lines have been drawn, old alliances shattered, friendships ruined, tridents thrown... the whole nine yards. But there's one problem with figuring out just how much Sean Smith is worth... doesn't that depend on how well he's played, and how well they think he'll play in the future?

I mean, it's only logical. If Sean Smith is in fact a lockdown corner, he's worth a ton of a money. If he's a mediocre corner we've all overestimated due to his impressive size and the fact that he gets to match up on the "easy" side of the field, then he's worth significantly less money.

Of course, the only way to know how well a corner played is to go back and re-watch every single coverage snap he took this season on All-22. And only a madman would do such a thing.

Fortunately for all of you, I am that madman. And that's exactly what I did. I went back and watched literally every coverage snap of Sean Smith's season. Every. Single. One. I have issues. But my issues are your gain.

While I watched Smith play, I charted "successful coverage" and "failed coverage" on each snap. A successful coverage is a play where the CB has the WR covered well enough that a spectacular throw or catch (or both) would be required for the WR to make a play. A failed coverage is where a run of the mill pitch and catch would do the trick. There is no such thing as perfect coverage in the NFL, so whether or not a catch was actually made doesn't factor in. It's all about whether the CB was properly in position.

Is this perfect? No. Not everyone's definition of a success or fail in coverage is going to be the same. I lean toward being a harsh grader to avoid homerism. But this is far and away the best method of discovering just how well a CB played throughout the year. Just for fun, I also tracked the number of times Smith was targeted, the number of catches he was personally responsible for allowing (and the yards / touchdowns given up), and the number of passes Smith defensed (including interceptions).

What's a good percentage of successful coverages vs. failed coverages? Well, again, it depends on the person doing the grading. I've done this type of thing for various Chiefs quarterbacks multiple times (for example, here's Marcus Peters' first half of 2015), and the standard I've come to set is 60-70 percent. If a CB has a "success" rate of 70 percent or higher, he's doing a very good job. Between 60-70 is acceptable work. Once a CB starts dipping below 60 percent, it's time to take a close look at him.

On a final note, there are some snaps I do not score. These are snaps where the defender plays zone coverage (without knowing his EXACT assignment it's impossible for me to try and grade it) or doesn't end up actually covering anyone. For example, when the play call is a quick WR screen to the opposite side of the field, the CB doesn't really cover anyone. This is a way to keep players from getting cheap "successes."

All right, that's enough intro. Without further ado, here are the results of 455 Sean Smith coverage snaps in 2015.

Now, I assume you've taken a moment to really go through those numbers. But there are a couple of notes I'd like to make.

For starters, Smith's overall success percentage is very good. It was better than I expected, actually. Which is fairly reflective of what the tape showed me; Sean Smith was a better, more consistent cornerback than I gave him credit for in 2015.

Even Smith's worst game of the year with regards to allowing big plays (we all knew it was going to be the Bills game) came with a not-horrific 62.2 percent success rating. Something I would note from that game; no matter how bad things got, it never seemed as though Smith allowed it to get to him. This was consistent throughout the year. Smith clearly has the short memory corners need to survive in the NFL. He might get upset after a bad snap, but I never saw him appear to get frustrated and out of his game for long.

Smith know how to play corner. His footwork is well above what many people expect from a 6'3, 220 pound player. It's actually what allows him to thrive the majority of the time despite not having good speed. Smith rarely takes false steps and generally does a very good job keeping his hips from getting twisted up by receivers. Additionally, Smith is rarely phased by the various jukes and stutters receivers throw his way to tray and get him turned around. He uses the sideline well, too, guiding receivers toward it to limit their space to make a play.

Quite simply, Smith just knows how to play corner.

Simple snap, but reflective of Smith's route anticipation and footwork (though he does take an extra step). pic.twitter.com/B6A7S9dsyM

— Seth Keysor (@RealMNchiefsfan) February 17, 2016

Like I said in the tweet, this is hardly a complicated play. But despite the fact that Smith doesn't possess very good quickness (one of his weaknesses, which I'll talk about shortly), he completely blankets this route. Anticipation and footwork. When you lock those things down consistently, you're going to be successful even if you don't have blazing speed.

And no, Smith does not have great speed or quickness. I wouldn't put him in late career Mike Brown territory or anything (to be fair, I'm almost certain I've got a step on the late career of Mike Brown), but it's not his strong suit. He HAS to be technically proficient if he wants to play at a high level. Because when Smith doesn't "win" with his technique, things tend to go sideways very quickly.

The biggest problem with not having good speed / quickness isn't the normal snaps. It's when things go wrong. One of the reasons, say, Phillip Gaines can get away with sloppy footwork is that he closes on receivers really, really quickly when he gets turned around. Smith doesn't have an extra gear to rely on. Additionally, he can at times fall victim to the Jeremy Maclin school of "if I'm even, I'm leavin'."

Sometimes the difference between a good statistical day and a bad statistical day in yards allowed is luck. pic.twitter.com/KcBIxCP6rm

— Seth Keysor (@RealMNchiefsfan) February 17, 2016

Smith has good position here initially (he does a great job on a lot of go routes). But once the ball is in the air, Marvin Jones just... leaves him behind. Smith loses a step looking for the ball and isn't able to make it up due to his lack of great speed.

Because of Smith's speed and quickness limitations (he doesn't have the smoothest hips you'll see either, though it's not to the same degree as his speed), there are certain kinds of receivers that give him problems. Sammy Watkins tore him up on multiple snaps. DeAndre Hopkins did as well. Of course, both of those guys are very difficult to cover for virtually any corner. More significant was the occasional fits lesser WR's gave him when they had good speed and quickness. Examples of this were in the Wild Card playoff game and against the Bears. In both games Smith got beat multiple times by relatively anonymous receivers.

That said, it's not as though Smith is constantly getting destroyed by anyone, even receivers that have physical traits that give him problems. Smith's anticipation and footwork often leave him stride for stride with such players, which is one reason his "success percentage" was consistently good.

The biggest reason Smith is able to be successful, though? Simply put, he's a strong man.

Because sometimes it's easier (and perfectly legal) to just shove the WR to the ground. pic.twitter.com/6vn9F7PO5l

— Seth Keysor (@RealMNchiefsfan) February 17, 2016

I re-watched that about 40 times, thinking I would see the part where the WR tripped over someone's foot. He didn't. He gets a little off balance and Smith just, you know, introduces him to the grass. He's a good dude like that.

Smith is a monster of a corner. As I mentioned earlier, he stands 6'3 and weighs 220 pounds. He's big for a safety, let alone a corner. Other big corners are often around 6'1 and 200 pounds. Smith is just in a whole separate league.

Now, the common perception (and one I used to share) is that Smith uses that size to constantly jam WRs at the line of scrimmage. Interestingly enough, he doesn't do it as often as you'd think. I assume this is in part due to his lack of recovery speed if he misses the jam. More often, Smith will mirror the WRs movements and start to run with him down the field. While doing so, he reaches out with one arm (his arms are ridiculously long) and uses it to slow down the receiver and disrupt his movement. It's a type of press, but a little different than most people expect.

Smith is able to keep receivers from gaining speed, from making sharp cuts, and generally doing what they're supposed to be doing with regards to their route. It is often VERY effective, and a huge part of why Smith is tough to beat consistently. He gets one of those long arms on you and suddenly your cut takes a half second longer, or you're not where your QB expects you to be.

Receivers aren't used to going up against corners who can actually physically overpower them. For many receivers, it's often the opposite. Smith excels against big, physical wide receivers because they can't do what makes them successful against him. When the Chiefs and Lions played, Smith and Megatron were just HAMMERING each other. It was like watching a game from the 70's.

You can't tell a lot about emotion from watching players on the field, but the body language of receivers going up against Smith often makes it look like they're having no fun whatsoever. Which makes sense. Imagine you're playing a guy you KNOW can't keep up with you, but the jerk won't take "his hands off you or leaning into you while you're running down the field.

Smith's physicality extends to contesting the ball as well. Remember the time Smith ran right through Emmanuel Sanders to pick off Peyton Manning? When Smith decides he's going to get the ball, he doesn't let stupid things like the presence of a wide receiver get in his way. It's a lot of fun to watch.

"That's great, but seriously, how much is Sean Smith worth"

I suppose we didn't come this far to just leave out the business side of things.

Here's the deal; I came into this fully expecting to write a review about how Smith is replaceable. After watching literally every coverage snap he took on all-22, I'm almost certain I'm wrong. Not many corners are able to have Smith's consistent success rate in coverage. And that's the name of the game; consistency. Smith is going to bring a pretty high level of play almost every week, and almost every snap. He doesn't really go on "cold" streaks or have days where he plays poorly.

Additionally, I need to note how tough it is to play corner in Bob Sutton's system. While the Chiefs do play some zone, the vast majority of their snaps involve all three corners (in today's NFL, it's often three corners on the field) playing on an island against receivers. I cannot possibly overstate what a difficult job this is for corners. It is arguably the hardest position to be consistently good at in the NFL right now (with quarterback becoming easier and easier to be at least decent).

With Sean Smith, the Chiefs have a player they know they can put in man coverage 90 percent of the time and he will more than hold his own. That's a major asset to this defense. Yes, Smith plays RCB, the "easier" side of the field, but he still consistently saw good receivers (receivers are constantly switching sides of the field) and did a solid job.

I'm a big fan of Phillip Gaines, but he has yet to show he can stay healthy. Additionally, he also hasn't proven he can be as consistently solid as Smith, or even close. Finally, the Chiefs have shown several years in a row that having two good corners simply isn't good enough anymore. If you don't want to have your slot CB picked on, you'd better be solid three deep if you're looking to run a lot of man coverage. If the Chiefs lose Smith, they're down to Marcus Peters as the only proven corner on the team who can stay healthy and perform. That's a great way to take a step backward.

Smith is not an elite corner, and the gap is wide enough that I would be against paying him elite level money (even though market forces generally dictate good players getting elite money, but that's a whole separate article). However, if Smith is willing to sign a contract that pays him an average of $9-11 million per year on average (and remember, the per-year hit will not necessarily be that $9-11 million), I think the Chiefs should jump at that chance.

That kind of money is the second tier of corner money, where you see Brandon Flowers, Aqib Talib, Jimmy Smith and other players of that caliber. It's a significant jump below the $14 million a year money you see thrown at guys like Richard Sherman and Darrelle Revis. And that's where Smith belongs as a very good, but not great, corner.

For most of the season I've leaned toward letting Smith walk and handing the reigns over to Phillip Gaines. Watching Smith in action has given me a new appreciation for how much he contributed to the defense. John Dorsey has shown me enough with regards to acquiring talent in the secondary that I trust his judgment. But if I were him I'd be willing to shell out pretty good money to keep Smith. He's a big, strong, technically sound corner who succeeds in coverage far more often than he fails while making receivers look miserable in the process. That's the kind of guy you keep around if you can.

Hopefully you enjoyed the first of the big offseason film reviews. There will be plenty more coming, with more of these types of in depth stats. It was a fun season. Let's make it a fun offseason too!