The Buffalo Bills started off the 2017 season hot, going 5-2 and shedding any talk about tanking. After taking care of the Oakland Raiders at home, the Bills headed east to face the New York Jets. And got whupped. Then they hosted the New Orleans Saints and got whupped in historic fashion. So then they tried heading west to right the ship against the Los Angeles Chargers. They got whupped. A once-promising season was in a dire situation as they prepared to face the Kansas City Chiefs in the extraordinarily hostile venue of Arrowhead Stadium. We all know how the season ended, but what happened to stop a three-game skid that earned some dubious records and help the team to the playoffs?

What the hell happened in the first place?

Let’s look (briefly) at the Marcell Dareus factor in points per game. For this exercise we’ll consider four different parts of the season and tie them to points per game.

With Dareus on the roster (week one through week seven against the Buccaneers) the Bills defense allowed 16 points per game.

per game. The Bills managed to hold the Raiders to 14 points. This is isolated by itself as the defense forced 4 turnovers. They didn’t manage more than 1 in any game after this except for the first meeting with Miami. The idea here is that they did fine without Dareus but it might have been a fluke.

The three-game skid (Jets, Saints and Chargers) had the Bills allowing 45 points per game

per game Following this three-week nightmare, they returned to 18 points a game.

How did they fix it?

Well if you’ve read the title of the article, you probably guessed they committed to the nickel defense. From a personnel perspective, this usually means you ditch a linebacker and add a cornerback or safety for a total of five defensive backs. For the Bills, this meant shifting time away from Lorenzo Alexander to put Leonard Johnson on the field more often. Here’s a data dump for you to peruse...

This table will set the stage for the next graphics which are much more friendly to the eyes. The first red line represents the before and after of the Dareus trade. The second is following the New Orleans game. This split was selected for two reasons. First, it was the second tail-kicking in a row and likely started a panic to make changes. Secondly, the next game saw massive changes on offense in the form of the Tyrod Taylor benching, so we can be pretty sure the coaches were trying a couple things to right the ship.

So how did this shake out with the two players we’re taking a look at? It’s pretty convincing actually if we look at average playing time. While there’s a big change in playing time for Alexander following the Dareus trade (17.5%), it’s even wider of a gap in the lens of the New Orleans disaster (23.3%).

We also see the same thing in reverse for Johnson. There’s a 3.6% increase following the Dareus trade, but a 14.1% difference if we split based on the New Orleans timeline. We have one more thing that makes it even more glaring.

This last one shows playing time percentage for both players for every game. Johnson lost about a game and a half due to injury in the post-New Orleans era, which forced more time Alexander’s way. There’s about a half-game missed by Johnson (Bengals) in the pre-New Orleans era as well. But the end result is that the average playing time using the New Orleans game as our split becomes even more conclusive when factoring in the injury.

Here’s some fun takeaways using the graph:

It’s nearly perfect that when one zigs, the other zags. Basically, this data is excellent for showing that the difference between nickel and “not-nickel” is the difference between these two players being on the field.

With Dareus in the lineup they did some tinkering between the two players, but were overall successful regardless of which one was on the field. In other words, Dareus allowed the rest of the defense some flexibility.

We’ll include Oakland through Los Angeles as part of the post-Dareus skid for personnel decisions. They initially went with Johnson and heavy nickel usage over Alexander. The next three games they adjusted with Johnson seeing decreasing reps two weeks in a row. Those happened to be disasters. Johnson saw increased time against the Chargers, but five first half interceptions make it hard to gauge the rest of the team.

That was enough of a sample size for the coaching staff and they rolled with Johnson moving forward. Johnson was hurt in the first game against New England and missed part of that game and the snowvertime win against the Colts.

Something to ponder here; New England was held in check (only nine points) into the third quarter in the first meeting. In the second game against New England, it was tied at 16 through two-thirds of the second game. A loss is a loss, but that’s a strong indicator that even against their toughest competition all year the defense had a decent plan.

Why did it work?

The turnaround in the context of scheme shifts is pretty close to astonishing. There was certainly some floundering after releasing Marcell Dareus, as you’d expect losing a cornerstone player. However, they managed to right the ship quite well (though it took a few games to sort it out).

But what’s the difference between Lorenzo Alexander and Leonard Johnson? Is Johnson that much better? Sort of.

It all comes down team chemistry. The Bills rely heavily on zone defenses which force players to make decisions based on who is in their bubble and which other bubble (defender) might they be heading toward. The end result is that it necessitated being able to react in any direction quickly. Agility and quick directional changes are critical. Simply put, the much smaller Johnson (5’8” and 198 lbs) can maneuver better in a zone than Alexander (6’1” and mid-200s).