The success of the Kansas City Chiefs defense in 2014 has been widely documented.
They finished No. 2 in the NFL in scoring defense, allowing just 17.6 points per game. They didn't allow a 300-yard passer or even a 50-yard completion all season.
Those numbers are kind of absurd in today's pass-happy NFL. The Chiefs were the only team in the NFL that could claim either of those statistics, let alone both of them.
One of the reasons for that success was the play of veteran cornerback Sean Smith, who completed one of the best seasons of his career last year.
According to Pro Football Focus, Smith was the No. 5-ranked cornerback in the NFL in 2014. He allowed just 57 percent of passes thrown in his direction to be completed, chipping in with nine passes defensed as well.
But that was last year, and rather than sitting back and marveling at his 2014 campaign, Smith spent his offseason focusing on the things he didn't do well.
"I actually had an opportunity to look at my season and work on all my negatives," Smith said. "I looked at all of the bad plays. The good plays—that's what I'm supposed to do. That's my job.
"But I was looking at the routes I got beat on and studying my technique in the second half. That way I know how to work when I'm fatigued and just build from there."
Before Smith would take any kind of credit for the success of the Chiefs defense last season, he pointed towards the guys making sure they were ready to play each and every week.
"First and foremost, you have to give credit to our coaching staff," Smith explained. "We're fortunate to have (defensive backs coach) Emmitt Thomas and (assistant defensive backs coach) Al Harris as our coaches, two of the greatest coaches who have ever played the game. They preach technique and they make sure we're prepared.
"Second, when you have Tamba (Hali) and 50 (Justin Houston) on the outside, you only have to cover for so many seconds. Those guys, especially 50, had an amazing year last year."
In 2015, opposing teams will try to figure out the best way to score against this Chiefs defense, which they weren't often able to do in 2014. In addition to the stars from last year, they will have the misfortune of dealing with the return of three-time Pro Bowl linebacker Derrick Johnson and defensive lineman Mike DeVito, not to mention first-round pick Marcus Peters.
But even with such a strong defense, chances are the threats will still be coming through the air.
Last year, the Seattle Seahawks ran the ball on 53.6 percent of plays, which was the most of any team in the NFL. They were one of only four teams in the NFL who ran the ball more than they passed last season.
The Oakland Raiders were on the other end of the spectrum. They threw the ball 65 percent of the time, which was the most of any team. There were eight teams who threw the ball on at least 60 percent of their plays.
Smith said this trend has been coming for a while.
"You don't see too many I-formations with big, bruising fullbacks anymore," he said. "You look over the years, even the padding has changed.
"Growing up, I used to watch the Steelers with (Levon) Kirkland, (Kendrell) Bell and those guys on the outside. Their pads were huge. Now these linebackers are 230 pounds and they're flying around. The game has changed; it's evolved.
"As a defensive back, I think it's even better because it puts more of us out on the field."
Smith said that he and his teammates understand and accept the challenge of being targeted more and more as the game evolves.
It's why they do what they do.
With that said for the Chiefs in 2015, don't expect Smith to simply rest on the season he had a year ago.
"Last year was last year," he said. "I did have a little success, but that's gone. I just have to learn from my mistakes and work towards 2015."
If the Chiefs defense is going to improve off a successful 2014 campaign, then it's nice to know the attitude is right where it needs to be in order to make that goal a reality.