Notre Dame football’s 49-10 demolition of Purdue moved the Fighting Irish to another level defensively, and it’s time to say what the tape has been screaming through four games. Notre Dame has the best defense in college football.

That’s not a statement made lightly, and the context matters. Purdue fell to 1-3, and they aren’t a great football team. Nobody is going to fight that point.

But what defensive coordinator Chris Ash’s unit has shown across every game this season goes far beyond one blowout. The pass rush, the secondary, the depth at every level of the defense, and the cohesive plan of attack have all been outstanding.

Chris Ash has flipped the script

Anyone who followed Notre Dame last season knows how critical the conversation was around Ash.

Through roughly two and a half games in 2025, the defense gave up a ton of points to Purdue in the first half and lost to Miami and Texas A&M. The criticism was warranted. But whatever come-to-Jesus moment Ash had with head coach Marcus Freeman last season, it worked. Notre Dame has looked like a different defense since that point in time, and the improvement has carried over into 2026.

There was a brief stretch early against Purdue where Ash looked passive, but then he flipped the switch.

Linebacker Kyngstonn Viliamu-Asa started blitzing from the second level with regularity. The secondary became more aggressive on the back end. From a play-calling perspective, the consistency has been miles ahead of where it was early in the 2025 season. The progress has been real, and it needs to be acknowledged even with the caveat that BYU, SMU, and Miami will provide much stiffer tests.

The pass rush is unlike anything in recent Notre Dame history

Defensive end Bryce Young was the first big winner from the Purdue game.

Young, the son of Bryant Young, has undergone a fascinating transformation. He started his career playing wide receiver before his body grew into a pass rusher. Last season as a first-year starter, he was listed at 6-6 and roughly 270-275 pounds but didn’t look as explosive as he did during his true freshman year in 2024.

This offseason, he trimmed down to the 260-pound range, shedding bad weight and finding his burst again.

The results showed immediately. On the very first play of the game, Young recorded a sack against Purdue quarterback Ryan Browne, who came in averaging 341 passing yards per game. Young set the tone, and later his pressure led to the sack-fumble that Drake Bowen scooped and scored for a defensive touchdown.

The difference between this Notre Dame pass rush and previous iterations is the depth. In past years, the Irish had a player like Isaiah Foskey, and then there was a significant drop-off to the second option, whether it was Jayson Ademilola, Jordan Botelho, or Justin Ademilola. This team can throw waves.

Across from Young, there’s Boubacar Traore, the most accomplished pass rusher on the roster, along with Keon Keeley, Loghan Thomas, and five-star freshman Rodney Dunham. At some point this season, don’t be surprised if Young or Keeley slides inside as an interior pass rusher to create even more chaos.

The defensive tackles are stacking up

Armel Mukam played what was probably his best game in a Notre Dame uniform for the second straight week. After getting benched the previous week in favor of Francis Brewu and Tionne Gray as starters, Mukam responded.

He was active in the backfield, contributed to the pass rush, and made plays in the run game. Brew continues to be a dynamite addition via the transfer portal.

The depth at defensive tackle is staggering. Beyond Mukam, Brewu, and Gray, there’s Elijah Hughes, Jason Onye and Chris Burgess when they return, and Sean Sevillano Jr., who continues to earn snaps. This defensive tackle room is fantastic, and the rotation keeps everyone fresh.

The secondary is the best in the country

The most impressive part of this defense is how it has handled adversity in the secondary.

Losing a preseason All-American like Brauntae Johnson, a player generating first-round buzz for the 2027 NFL Draft and arguably the most impactful defender in the back end outside of Leonard Moore last season, would cripple most teams.

Notre Dame replaced him with Luke Talich, a 6-4, 220-pound safety who was arguably their best defensive player against Michigan State. When Tallich needed minor surgery earlier this week and was unavailable, five-star Joey O’Brien stepped in to start next to Adon Shuler. It is an embarrassment of riches.

DJ McKinney has been fantastic opposite Leonard Moore at cornerback. Christian Gray’s move into the slot has been quietly effective. The fact that Gray hasn’t been noticed much is a positive. It means he’s playing sound football and staying in the right spots after being extremely up and down the last couple of years as the field corner.

This is about more than star power

Kyngstonn Viliamu-Asa continues to be a force at linebacker. Drayk Bowen, Jaiden Ausberry, and Jaylen Sneed add even more talent on the second level. Notre Dame’s defense isn’t the best in college football solely because of star power from players like Moore, Traore, and Viliamu-Asa. I

t’s because the depth behind those stars is something the program simply hasn’t had before. The defensive line depth, the secondary depth, all of it has been outstanding to watch.

The goal isn’t to crown this defense after beating Purdue. The goal is to beat BYU, beat Miami, make a deep playoff run, and win a championship. Four games into the season, Chris Ash’s unit has earned the right to be called the best defense in college football.

Now it’s about proving it when the competition stiffens.