NFL Defensive Statistical Analysis from the 2020 Season

Do you want to know where your team ranks amongst all 32 NFL teams on defense? If you do, you're in luck because these are the results from my in-depth statistical analysis.

Cool Chart, but What Does it Mean?

To properly analyze each NFL team's defensive performance, I used Z-Scores as the foundation. A Z- Score is a means of creating a standardized score by calculating the number of standard deviations a value, otherwise knows as a raw data point, is above or below the mean value. The first two steps were to acquire the raw data for each team from Pro Football Reference (https://www.pro-football-reference.com/years/2020/opp.htm), and then find the mean value and standard deviation of all 48 columns of data that I wanted to assess NFL defenses on. All 48 columns originated from one of these five statistical categories; passing defense, rushing defense, defensive scoring, defensive conversions allowed, or defensive drives allowed. After those key foundational steps were completed, I calculated each team's Z-Scores for every category before finally averaging their 48 Z-Scores to create a final, individual defensive Z-Score which was presented in the graphic above. I also made sure to attach a table with each team's score below so you could see their numeric score as well...

What Are Some of the Major Takeaways?

With a statistical study of this size, there is a multitude of realizations you can take away from this study. However, I'm going to elect to discuss the takeaways I thought were the most interesting, starting with New England Patriots. As we all remember from the start of free agency, the Patriots spent big money on notable free agents this offseason where they invested heavily on both sides of the ball. As an already above-average defense with a score of 0.133, the additions of Matt Judon, Kyle Van Noy, Jalen Mills, Davon Godchaux, Raekwon McMillan, Henry Anderson, along with keeping around one of their best defensive linemen, Lawrence Guy, the Patriots defense has gotten much better at an unprecedented rate. Judon, potentially the most notable defensive acquisition the Patriots had this offseason, is 29 and currently in his prime. He had 15 QB knockdowns, 6 sacks, 50 total tackles (32 of which were solo tackles) and he had a career-low 7.4% missed tackle percentage in only 14 games this season. The new and improved Patriots defense will feature Lawernce Guy, Davon Godchaux, Henry Anderson, and second-round pick Christian Barmore on their defensive line, Judon, Van Noy, and Chase Winovich as the 3-4 OLBs rushing the passer, Dont'a Hightower Ja'Whaun Bently, and Raekwon McMillan rotating as the ILBs, and an elite secondary headlined by one of the best corners in the game, Stephon Gilmore. The additions the Patriots made this offseason and getting players returning from opting out of last season due to COVID-19 should dramatically improve and I don't think it's a stretch to expect the Patriots to finish a top ten or potentially top-five defense next season.

Next, this study explains why the Tennessee Titans unable to make a deep playoff push. Even with arguably the best running back in the NFL, Derek Henry, a top ten and potentially the most underrated quarterback in the league, Ryan Tannehill, and a young difference-maker receiver, AJ Brown, the Tennessee defense will be what holds them back for another year. The Titans had the 4th worst defense last season, which lead them to an early playoff exit in the Wild Card game against Baltimore. The acquisitions of Bud Dupree and Denico Autry will have an impact on day one, but this team is still not good enough defensively to stop the high power offenses they will have to play to make a deep playoff push like the Chiefs, Bills, or Ravens. The Titans had the third-fewest sacks last season with 19, and they had the lowest sack percentage out of all 32 NFL teams. That is not an issue that can be fixed by bringing in one or two free agents, that is a team-wide issue. Not to mention, the Titans have gotten significantly worse in their secondary this offseason by losing Malcolm Butler, Adore Jackson, and Kenny Vaccaro. Currently, their day one starters at cornerback are Janoris Jenkins who will be 33 next season and has had a mediocre career with the St. Louis Rams, New York Giants, and the past two seasons in New Orleans and hasn't played a full season since 2018, and Caleb Farley, their first-round draft selection in the 2021 NFL draft. Farley was a player I liked from the beginning of the draft process, but with injury concerns in his back, throwing him out on the field day one was not a situation I thought would suit him well. If Farley was in a position where he could start the preseason on the PUP (physically unable to perform) list so he could still work out and attend team meetings, and then be an active participant in team drills and practice when the season begins while not playing him in a game situation until week five or six, that would be an ideal situation for him. However, he will not have that luxury in Tennessee where they will need him as a day one starter. Overall, Tennessee undoubtedly improved their defense this offseason, but is it enough for them to make a playoff push against some of the elite AFC offenses? I just don't see it.

Finally, I want to talk about the Detroit Lions, the worst defense last season in the NFL that made moves this offseason to set them on an upward trend. Detroit was the worst defense last season and by a notable margin as well. However, they prioritized building the foundation for the future of their franchise in the trenches. The Lions spent their second-round pick on Levi Onwuzurike, the defensive tackle from Washington University, and their third-round pick on Alim McNiel, the defensive tackle from NC State. The Lions also acquired Michael Brockers in a trade with the Rams this offseason only costing them a 2023 7th round selection. Along with a healthy Trey Flowers and Romeo Okwara, who is coming off a career-high ten sack season, Detroit Lions fans have a reason to be hopeful on the defensive side of the ball. Hopefully, Jeff Okudah has a bounce-back season and plays like draft experts expected him to play after being selected third overall in the 2020 draft. But the Lions also added Quinton Dunbar, who played for Seattle last season before spending the first five seasons of his career with Washington and Ifeatu Melifonwu, their other third-round selection in the draft this year. Detroit still has work they need to do to address their weak linebacking core and continue to improve their secondary, but the culture Dan Campbell is establishing in the wake of Matt Patricia and Brett Holmes as their new General Manager, Detroit is trending upwards. Detroit defined themselves this season as a team that is going to be strong on the defensive side of the ball. Next, I expect them to address their lack of weapons on offense and then ultimately replace Jared Goff, and pretty soon Detroit isn't a joke of a franchise anymore.

Honorable Mentions: The Cleveland Browns identifying and addressing their two weakest positions on defense in the first two rounds of the draft, The Houston Texans not improving on the defensive side of the ball besides adding Desmond King, and are the team I predict to be the worst defensively in 2021, and the Carolina Panthers as the sleeper team I expect to surprise NFL fans defensively in the upcoming season.