I try my best to be a tape-grinder, analyzing film to inform my opinions regarding a team or player. However, given the moratorium on college football film, it is challenging to locate film for Boston College’s defense in 2021. I could watch the broadcast copy. However, the broadcast angle’s limitations on defense are more pronounced than the ones on offense. This article dissects Boston College’s defense from a statistical and analytical perspective.

In this article, I use data from Sports Info Solution (“SIS) and Pro Football Focus (“PFF”). SIS’s statistical portal provides excellent data regarding a team’s tendencies and usage of various personnel, formations, and alignments. Most people know PFF for their grading of players, but PFF also has excellent statistics for individual players.

As the passing game has taken over football and defenses have commensurately evolved, defensive personnel groups are typically divided into two families: Base and Nickel. Base covers traditional defensive formations (e.g., 4-3 and 3-4) with four defensive backs on the field. Nickel, therefore, deals with defensive personnel packages with five defensive backs (e.g., 4-2-5, 2-4-5, 3-3-5). In the NFL, the usage of nickel defense has continued to increase every year. Given the general increase in passing, along with the extant Air Raid teams and the triple option's slow demise, this trend also follows in college football.

However, this does not account for all defensive plays. The remainder is typically categorized into three buckets: Dime or Dime +, Big, and Goal Line. The latter obviously deals with short-yardage formations typically featuring three or fewer defensive backs. Big defensive formations are somewhat ambiguous, as they also usually have three or four defensive backs but feature heavier personnel in the front seven of the defense. For the purposes of this article, I will combine Goal Line and Big into a “Heavy” personnel grouping.

Dime or Dime+ deal with the lighter defensive formations. While the conversion rates don’t make perfect sense, as the currency value of the defensive package increases, so follows the number of defensive backs. Dime, or sometimes Dollar, packages feature six defensive backs, while Quarter packages feature seven or sometimes more. Ironically enough, despite the increased passing in the NFL, the usage of Dime+ packages has decreased in the past two seasons.

Boston College Defensive Personnel Tendencies

We’ll begin by dividing Boston College’s defensive personnel tendencies into the four prominent families: Heavy, Base, Nickel, and Dime+ (data from Sports Info Solutions ).

I’ll admit: I think there is an error in the data regarding BC using Heavy personnel groups. I’m fairly certain they used Heavy personnel more than only twice. But the general trend of the data stands; BC spent almost three-quarters of their defensive snaps in Nickel personnel. Given that tendency, let’s break out the Nickel personnel into their various formations.

Given the storied history of the 3-3-5 defense , one might be surprised to find that as BC’s most favored defense in 2021. However, these numbers are somewhat misleading. When delineating personnel groupings, a player is usually divided between a defensive lineman or a linebacker by his stance. If he is in a three-point stance, he is a defensive lineman; if he is in a two-point, he is a linebacker. Especially in the latter half of the season, Boston College utilized what would be coded as a 3-3-5 defense, where one “defensive end”, usually Marcus Valdez , would rush off the edge from a two-point stance.

This differentiates BC from the 3-3-5 Stack made famous by Arizona State and San Diego State . It also unifies the majority of the Nickel defenses BC employed; if one defensive end can stand up (3-3-5), why not both (2-4-5) or neither (4-2-5)? The exception is the 1-5-5 defense, although I suspect this involved several defensive end-types rushing from two-point stances. The 1-5-5 look was only employed on obvious passing downs (3rd and 4th downs with at least five yards to go).

Moving into the Modern Era

Nevertheless, this is also very telling of the future direction of BC’s defense. AJ, myself, and many other BC fans have been concerned about the size, or lack thereof, of some of BC’s defensive line recruits. Players like Donovan Ezeiruaku, Neto Okpala, Quintayvious Hutchins, and several freshmen are not built like traditional 4-3 defensive ends.

However, these defensive tendencies show that Jeff Hafley, Tem Lukabu, and the rest of the coaching staff are primarily concerned with recruiting players that can get after quarterbacks with speed. In today’s college football, where passing and specifically the RPO reign supreme, being able to affect the quarterback quickly is paramount. Therefore, it is clear that Hafley and Lukabu have a specific plan for this defense.

One other interesting note: compared to the rest of the FBS (130 teams), Boston College was in the top 50 in usage rate for the three main Nickel personnel packages. This tracks with my theory about BC unifying their Nickel personnel packages while switching their edge rushers between two- and three-point stances. But it also displays how the coaching staff is willing to be flexible and creative with how they use players; they put them into the best positions to succeed even if it doesn’t perfectly adhere to the core tenets of their defensive philosophy.

What Does it Mean For 2022?

Boston College retains most of its experience and production on defense. Long-time starting cornerback Brandon Sebastian moved onto the NFL, along with run-stuffing extraordinaire defensive end Brandon Barlow. The rest of the defensive line returns, along with defensive tackle Chibueze Onwuka. The front seven performed inconsistently last year, but the young players now have a full season of experience under their belts. The entire defensive coaching staff returns, so I would not expect much philosophical change.

I expect Tem Lukabu and Jeff Hafley to continue diversifying and innovating on defense. In 2020, they were pretty vanilla with their personnel usage; they used a 4-2-5 defense on 56% of all defensive plays. In 2021, they used significantly more variety, indicating they were more comfortable with the players on the roster. The general trend towards lighter defensive personnel should continue; I would also expect the coaching staff to move towards equilibrium regarding the distribution of Nickel personnel usage rates.

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