Here's what makes Sean Smith so good for the Kansas City Chiefs

Kansas City Chiefs corner Sean Smith earned himself a spot on Pro Football Focus' yearly Top 101 Players list. Grading out as the 44th best player of the year, Smith showed more this past year than he did in his previous five, helping to solidify a secondary that was a major concern at the end of 2013.

Smith started his career as a second round selection for the Miami Dolphins in 2009, where he played four years of average ball by PFF standards. It wasn't until coming to defensive coordinator Bob Sutton's squad in 2013 that he began to move forward. 2014 was his breakout campaign.

Perhaps the most famous play Smith made last year was one that, like the rest of his season, won't make it on to any highlight reels. But it was big. The Seahawks were down by four in the fourth quarter, with a fourth and goal at Kansas City's two yard line. In a decision that will remind us now of the Super Bowl, Seattle chose to pass instead of run. But Smith recognized the cross and very quickly passed his route off and picked up instead receiver Doug Baldwin as he attempted to fade into the end zone corner. Smith bumped him off his path to prevent what would have been an easy touchdown.

It was a quiet "Play of the Game" candidate that helped the Chiefs beat the defending Super Bowl champs. On a day where Richard Sherman was on the opposing team, Sean Smith gave up only one catch for five yards on four targets, and made plays like the one above that stat sheets always miss.

Smith's play, perhaps for that reason, doesn't seem to be making too much noise outside of Kansas City. Though that will also happen when you miss the playoffs and your team possesses a pass rush that dominates quarterbacks and, deservedly, headlines. All of the above will change for the better if the veteran defensive back continues his current standard of play.

Pro Football Focus (PFF) graded Smith the fifth best corner in their overall grades, and the third best if we just look at coverage. Ahead of him stands only Indianapolis' Vontae Davis and Denver's Chris Harris Jr.  So, yes, PFF says our boy Smith was better in coverage last year than both Darrelle Revis (fourth) and Richard Sherman (fifth).

All this despite only managing one interception, and dropping a few potential ones along the way. While the lack of interceptions on defense was a big let down in 2014 given how this team relied on them in Andy Reid's first year, it doesn't make too big a difference to Smith's overall game, nor the way we should analyze it. Interceptions can be a fluky and random occurrence -- passes defended, not so much. Only seven corners defended more passes than Smith last year, who batted, stopped, punched, flailed, or otherwise-interrupted nine potential receptions. If that keeps up, the interceptions will come.

In watching film of Smith against Arizona and New England in particular (his two best-graded games of the year), he was consistently in good position against his man, forcing Drew Stanton and Tom Brady, respectively, to look elsewhere, or risk a pick. In the first contest, Smith put the game further out of reach with an easy haul of a third quarter Brady pass. In the second, he reduced Stanton's options through the air, nearly coming away with an interception against him, as well.

Smith managed to defend two passes against the Cardinals, and one against the Patriots. He gave up only four receptions on 10 targets for a mere 40 yards -- a lonely three of which were considered Yards After the Catch (YAC).

In-fact, of all 73 cornerbacks to see at least 20 snaps a game, Smith ranked 17th in YAC allowed. 168 yards altogether through 16 games is pretty darn good. But perhaps a better way to judge the effectiveness of Smith in staying close to his man and closing fast is to look at his YAC given up per reception. By my count, he was top 15 in the NFL last year out of the same 73-man field, allowing only 3.42 yards of YAC per reception.

That does leave room, though, for some improvement. PFF credited Smith with five missed tackles in coverage last year, which was more than your average corner. If Smith can work on that area of his game, which appears to be his only statistical weakness, the YAC allowed will drop even further. Add a highlight-reel pick or two and you are looking at a guy who, by the end of 2015, won't just be making it on the PFF Top 101 list, but will have the league discussing him in the same breath as the consistently-vaunted Revis and Sherman.

To the tape.

No. 21 on All-22

Below are stills from a few plays against New England in Week 4 and Arizona in Week 14.  We start with one from Week 4.

Julian Edelman (blue route) is running an out about 20 yards up field while Brandon Lafell (white route) streaks down the sidelines. Smith (underlined red) is in man coverage on Lafell. Ron Parker is the man all alone up top, meaning the Chiefs are giving Brady a single-safety look, and Smith can't let Lafell beat him deep.

What we see here is Parker in no position at all to do anything about Lafell. That likely wasn't his role, anyways, as Smith was meant to stay with him down the sideline. This means the play-call for New England is really good given Kansas City's coverage. The rest of the defense is in shallow zones, meaning Edelman (blue) has a good amount of space to work in while Lafell drives Smith deep and out of the play.

But Smith (red) does a great job seeing Brady and comes back to interrupt Edelman's route, letting Lafell continue down the sideline, unmarked.

Just a really great and well-executed decision by Smith to drop out of his coverage. He makes this catch tougher than Edelman is prepared to handle and almost comes away with the pick. Nearby, Bill Belichick looks on at what was to become one of the biggest beatings his team has ever taken. More of that, please.

Fast-forwarding to Week 14 now, we get a day in which Sean Smith did very well containing both Larry Fitzgerald and Michael Floyd.

Here we have a bunch formation for Arizona while the Chiefs are in nickel.

CB Chris Owens will blitz (white arrow) after faking coverage. Parker (yellow) will come down to pick up any routes near the sideline. Husain Abdullah (white), lined up above in a linebacker position, will drop immediately to his left to catch any inside routes. Smith, in the mean time, seems to be lined up exclusively on Fitzgerald (underlined red). Either that, or it's his job to watch anything deep as the de facto safety.

An interesting mixture of zone, man, and blitz, depending on your interpretation. I'll leave it to someone who knows more about these things than I do to give a more definitive answer. Regardless, it's matched by an equally interesting play-call from the Cardinals.

While one receiver (black arrow) flies straight to drive the coverage down-field, Fitzgerald (red arrow) will sit down about seven yards up-field. Parker has to watch the route at the 20 yard-line, heading towards the flat. The Cardinals do a good job of picking up the blitz and Stanton delivers a well-timed pass to Fitzgerald.

It had to be well-timed to get there because Smith, once again, spotted the route and responded to it quickly. He is there to meet Fitzgerald for the catch, just as he met Edelman above; but this time Fitzgerald makes a strong snag.

And it would be the future Hall of Famer's only catch against Smith on the day, totaling seven yards.

This next play is similar. Arizona offers a bunch formation with a go route as one of its pieces. This time, however, Fitzgerald (red route) and Floyd (black route) are going to run roughly matching outs 10 yards up-field.  The Chiefs appear to be in man coverage, lined up just as you see them -- 1, 2, 3 -- against the three Cardinal receivers. This puts our protagonist, Smith (underlined red), on Floyd.

In what looked in real-time like a very confusing mesh of red jerseys flying side-by-side, Floyd does eventually motion toward the sidelines and Smith makes an aggressive dart to stay with him.

He makes such a great cut on the route that he manages to squeeze in front of Floyd. The ball is ever-so-slightly underthrown, but I think Smith would have been there to get in front of it no matter what. As it happens, the ball (brown line) is nearly picked off. The potential interception is dropped, but that doesn't diminish the athletic play by Smith to break up a 1st down.

It looked more fun full-speed, but I'm afraid you'll just have to accept my measly screenshots and MS Paint scribbles.

Here we have Smith (underlined red) on Floyd (black route) once again. Owens (yellow line) is going to play a shallow zone to match Smith's deep one.

Floyd runs a perfect route between Owens (yellow), who looks to be playing a little too shallow, and Smith, who, in ensuring Floyd doesn't get past him deep, gives him just enough cushion for the comeback.

The throw is an excellent one and the catch is even better, as Floyd slid his left foot along the grass while all his momentum took him out of bounds. It looked as if he was swept quickly aside by an oncoming train, yet he managed to get both feet down.

This was a 16 yard gain and the biggest Smith gave up on the day -- and, arguably, it wasn't Smith who allowed himself to get pushed too deep, but Owens who cut his zone off too shallow. Either way, I suppose the thing to take from this is that it took a lot of things going very right for Arizona to get the better of Smith on one play.

Here we have one last play on a big third down late in the game. Smith is once again on Floyd.

The blitzing Josh Mauga (white arrow) is a second late, as the ball has already left Stanton's hand. Smith is breaking on the route while Floyd, whether due to a poor throw or poor route, is facing inwards for a throw directed towards the sidelines.

Though it may have been irrelevant, as Smith closes on the play rapidly and prevents the completion.

These two games were considered the best of Sean Smith's season by PFF. They came, respectively, and at least in part, against one-day Hall of Famers Tom Brady and Larry Fitzgerald. They moved him from a no-show on the Top 101 Players list a season ago, to 44th this time around. Can he repeat the performance in 2015?