The Ravens’ offensive metamorphosis from a mediocre pass-heavy scheme with quarterback Joe Flacco to a dynamic spread-option running scheme helmed by rookie Lamar Jackson has received most of the attention during Baltimore’s run to the postseason. There’s a good reason for that—that new-look offense is like nothing we’ve seen this year, and Jackson’s been incredibly fun to watch—but while the near-complete offensive shift certainly helped the Ravens win six of their final seven games and secure a playoff berth, it was their rugged, hard-nosed defense that provided the foundation for that midseason turnaround.

Riding talent at all three levels of the scheme and coordinator Don Martindale’s aggressive, blitz-happy mindset, Baltimore’s stingy defensive unit looks ready to make some noise in the NFL’s wild-card weekend. That group finished second only to the Bears in points allowed (17.9) this year, tied for first in yards per play allowed (4.8), third in yards per drive (26.3), and second in opponent first downs per game (17.9). The Ravens’ pass defense suffocated quarterbacks and receivers all year, ranking third in DVOA, sixth in pressure rate (32.0), 10th in sacks (43), second in opponent passer rating (80.6), second in opponent yards per pass attempt (5.8), first in opponent completion percentage (58.4), and first in opponent incompletions per game (15.0). They were strong against the run, too, ranking sixth in DVOA, third in yards per attempt (3.7), and fourth in yards per game (82.9). And, crucially, this unit seemed to get better as games went on, finishing first in second-half points allowed (6.9 per game) and first in fourth-quarter points allowed (3.6 per game).

Against Philip Rivers and the Chargers’ explosive offense on Sunday—and on the heels of a regular season that was defined by an explosion of high-flying offenses across the league—the Ravens have the chance to remind everyone that defense still matters.

Despite ranking among the best defenses all year, the stage was set for another Week 17 disaster for Baltimore. Last year, the Ravens faced an all-too-familiar win-and-you’re-in playoff scenario in their regular-season finale against the Bengals. Carrying a slim 27-24 lead with 53 seconds to go in that game, Baltimore’s defense collapsed at the worst possible moment, surrendering a 49-yard touchdown to Cincy receiver Tyler Boyd on what should’ve been an easy game-sealing stop on fourth-and-12. Fast-forward to Sunday and it was deja vu all over again: Holding a 26-24 lead, and with a postseason berth on the line, Baltimore was faced with stopping Baker Mayfield and the Browns, who had first-and-10 from the Ravens’ 39-yard line with 1:18 to go. No pressure.

Instead of playing it safe, though, Martindale threw caution to the wind. On first down, the 55-year-old play-caller dialed up an all-out seven-man blitz, dropping safety Eric Weddle from his spot deep and down into the box just before the snap to bring pressure off the edge. Mayfield reacted quickly, unleashing a deep pass toward the sideline to a streaking David Njoku. But veteran safety Anthony Levine, trailing in coverage, knocked the pass out of Njoku’s hands at the last second.

On second down, the Ravens didn’t let up, sending a six-man blitz into the teeth of Cleveland’s offensive line. The coverage held up again: Mayfield’s throw toward the left sideline was behind Jarvis Landry, allowing cornerback Jimmy Smith to knock it away.

On third down, more of the same: Weddle flew downfield at the last second on another seven-defender blitz. Mayfield looked to his right and tried to fit a pass to Njoku on a slant but Levine came through once again, batting the pass away.

That set up the pivotal fourth-down play. Martindale again brought the heat, sending six defenders on a blitz at the snap. Browns guard Joel Bitonio slid to his right to pick up middle linebacker C.J. Mosley, and when Mosley realized he wouldn’t be able to get through to pressure Mayfield quickly enough, he instead retreated back and to his right, looking to take away one of the Browns quarterback’s passing lanes. That’s exactly what he accomplished: When Mayfield tried to hit Duke Johnson on a slant to his left, Mosley reached up and snagged the pass to seal the win.

Overall, the finale against the Browns wasn’t the best performance of the year for the Ravens defense, which gave up 376 passing yards and three touchdowns to the playmaking rookie, and surrendered seven passes of 20-plus yards or more (including three of 40-plus yards). But in the end, Baltimore bowed up and made its biggest stop of the season, getting back to its roots as the dictator on defense by aggressively attacking the Browns on those four crucial plays. In the process, the Ravens illustrated how that unit has been one of the league’s best all season, pairing a hounding, athletic front seven (headlined by Mosley, interior linemen like Brandon Williams, Chris Wormley, Brent Urban, and Michael Pierce, and edge rushers like Terrell Suggs, Matt Judon, Za’Darius Smith, Tim Williams, and Tyus Bowser) with a tight, disciplined coverage unit on the outside and over the middle (with cornerbacks Jimmy Smith, Marlon Humphrey, Brandon Carr, and Tavon Young). That combination gave Martindale the confidence he needed to send four straight Cover Zero blitzes right at Mayfield. As he said after, “To win the game, we’re not playing some zone.”

On the day, Baltimore—one of the blitz-happiest teams in the NFL all year—sent five-plus rushers an incredible 22 times, holding Mayfield to a paltry 2.5 passer rating on those plays. Pairing pressure up front with blanket coverage on the back end is obviously extremely difficult for opposing quarterbacks to deal with, but it’s not just that the Ravens bring extra rushers so often—it’s how they bring them.

When Baltimore played the Chargers—their upcoming wild-card opponent—two weeks ago, it frequently lined up six, seven, or sometimes even eight players right on the line of scrimmage, confounding Rivers while frequently forcing hurried, off-target throws. In that 22-10 victory in L.A., the Ravens sacked Rivers four times and hit him another eight. On this play, Martindale sent five defenders, with linebacker Patrick Onwuasor running straight through the blitz-pickup attempt by running back Justin Jackson.

On a blitz later in the game, Onwuasor sliced to his left, allowing defensive end Brent Urban to stunt underneath him and run straight through Melvin Gordon for the sack.

Onwuasor tried another stunt later, and when the Chargers failed to pick it up, he just continued upfield to sack Rivers himself.

By placing his linebackers—and at times, defensive backs—up close to the line of scrimmage, Martindale has an endless variety of blitz looks at his disposal. He can drop any combination of linebackers into coverage while sending others up on a blitz (and vice versa), and he can mix and match which of his outside linebackers rush, too. That makes it tough for the quarterback, offensive line, and running backs to identify where pressure is coming from, and then gives those opposing quarterbacks very little time to do much with the ball. These looks helped the Ravens hold Rivers to a then-season-low 181 yards and 51.7 passer rating while limiting the Chargers to a season-low 198 yards of total offense, and they’ll likely be a key strategy for Martindale again on Sunday.

On paper, the Chargers-Ravens wild-card matchup has all the makings of a heavyweight bout. Few teams were as balanced on offense this year as Los Angeles, which boasted the sixth-ranked rushing offense per Football Outsiders’ DVOA with Gordon, Jackson, and Austin Ekeler, and the second-ranked passing game per DVOA with Rivers, Keenan Allen, Mike Williams, and others. That unit will have tough sledding, though, against a Baltimore squad that finished the year at or near the top of just about every meaningful defensive category.

The Ravens’ one weakness, if you can really call it that, has been a relative lack of takeaways (on the year, they ranked 22nd leaguewide in that category with 17). Still, turnovers often come in bunches, and the Ravens have notched six takeaways in their past two games, including three (two picks and a massive forced fumble) in their Week 16 win over L.A.

The Ravens are going to have their hands full with the Chargers on Sunday, but with their tough, experienced defense working in concert with a ball-control offense (which ranked first in time of possession this year, helping to keep their defensive counterparts fresh throughout the game) Baltimore looks exactly like the type of team no one wants to face.