Bill O'Brien Addresses Why Boston College Football's Defense is Among Worst in FBS

The Eagles are allowing 431.7 yards per game and have surrendered 44 touchdowns, which ranks third-to-last in the nation.

Nov 8, 2025; Chestnut Hill, Massachusetts, USA; Southern Methodist University Mustangs tight end Matthew Hibner (88) runs for a touchdown against Boston College Eagles defensive back Marcus Upton (20) during the second half at Alumni Stadium. Mandatory Credit: Eric Canha-Imagn Images | Eric Canha-Imagn Images

There is no argument to justify it at this point. Boston College football’s defense is statistically one of the worst in college football, and Bill O’Brien and the defensive coaching staff have not been able to effectively shut down an opposing offense since the Eagles’ Week One blowout win over Fordham.

Whether it’s poor coaching or lack of talent and depth, or a mixture of both, O’Brien fully acknowledges that BC’s defensive woes to the extent it has displayed this season are completely unacceptable.

“I think it’s a little bit of both, right?” O’Brien said on Thursday. “I’m not going to go down the injury road or anything like that. I just think that we all, on both sides of the ball, … we just haven’t been able to, you know, it’s been too inconsistent."

Inconsistent is a mild way of putting it.

The Eagles have allowed 4,317 yards on defense—a rate of 431.7 yards per game—including 44 touchdowns, which ranks third-to-last in all of FBS.

BC ranks 116th in the nation in total sacks (14.0) and is tied for 123rd in total tackles for loss (40.0).

Linebacker Owen McGowan said it comes down to a simple lack of execution—not broken coverages or failed assignments.

“Missed tackles, I think, is the biggest thing,” McGowan said. “I think a lot of times we’ve been in good positions to make the plays, we just haven’t necessarily made them. I don’t think guys are missing assignments or like blow coverages. I think it’s missed tackles and just not making the play when you’re there.”

O’Brien refuses to go down the injury route as an explanation for BC’s abysmal defensive play, which any head coach at the college or professional level would do. But there is also some truth to the fact that injuries, which have piled up drastically throughout the season, are hurting the defense’s chances more than O’Brien might attest to because of simple depth deficiencies.

Boston College has 23 players listed on its availability report. Georgia Tech has one. pic.twitter.com/pAHjnq2Cds

— Trevor Hass (@TrevorHass) November 14, 2025

There are already a number of true freshmen, freshmen and sophomores who have been inserted into games this year on a regular basis. With very limited game exposure, it makes sense for there to be occasional fallbacks. 

This level of consistent collapse in containment, however, is in the tier of intolerable.

“At times, we look really good, right?” O’Brien said. “If you go back to the beginning of the SMU game, or parts of the Notre Dame game, on both sides of the ball, we looked really good. But, obviously, too many times it has not been good enough. So we’ll have to do a deep dive on that after the season.”

The most glaring area of the defense, besides the sheer number of chunk plays it has relinquished—resulting in excessive explosive plays—is the defensive-line pressure.

It is more transparent than ever just how much Donovan Ezeiruaku carried BC’s defensive line in 2024, when he manufactured 16.5 sacks—which is 2.5 more than the Eagles have recorded as a team this year—and won ACC Defensive Player of the Year honors.

“We haven’t been able to generate the same amount of pressure,” O’Brien said. “Obviously, Donovan was an elite player. … We knew we weren’t going to be able to replace that. Quintayvious Hutchins has done a hell of a job, but at the end of the day, Donovan was, in my opinion, a first-round draft pick.”

O’Brien added: “So we tried to generate it through, you know, pressure and things like that. Just having, you know, at times it’s come home, but not, clearly, not enough. So we got to really look at that in the offseason.”

According to O’Brien, defensive coordinator Tim Lewis, who is in his second year with the program, has not done anything radically different than last season in terms of the style and scheme.

“There’s some things that we did differently, but I don’t think the style changed,” O’Brien said. “It’s a multiple defense. We play Okie, we play four-down, we play a bear front. We play nickel, we play dime, and, obviously, we play base defense. So we did that last year. I don’t think the whole thing, I don’t think the styles changed that much.”

As it turns out, maybe Lewis should have done something to change the style, because without Ezeiruaku, BC’s defense has looked like a shell of its former self.