The Buffalo Bills’ defense has been one of the bright spots of the 2017 NFL season thus far. In fact, their defense ranking as highly as it has in most categories is one of the biggest surprises of the season. Through the first four games, the Bills defense was a revelation, and through the last four, they’ve been solid. Here is how we scored each individual part of the defense in the second quarter of the season.

Defensive Line: B-

Buffalo’s defensive linemen started off hot, but their play has trailed off considerably over the last four games. The Bills’ defensive linemen combined for 7 sacks through four games, and through 8 games, the defensive line has 10 sacks. None of the four players who had sacks in the first four games—Jerry Hughes (3), Shaq Lawson (2), Kyle Williams (1), and Eddie Yarbrough (1)—have a sack in the last four games. Ryan Davis, Cedric Thornton, and the since-departed Marcell Dareus have a sack apiece in quarter two of the season. In fact, the Bills only have those three sacks in their last four games, bringing their season total to 14. They had 39 sacks as a team last season, and at their current pace, they’ll only make it to 28 for this season. While the pass rush has lessened, the run defense has continued to look strong, as Buffalo allows 94.4 rushing yards per game, good for 7th in the league. That’s including a miserable performance on Thursday night against the New York Jets where the Bills allowed 194 yards on the ground in a 34-21 loss.

Linebackers: B+

For a group that was viewed so poorly, they have really held their own this year. Preston Brown has been solid, if unspectacular, as the team’s middle linebacker. He is fifth on the team in solo tackles with 27, but his 37 assisted tackles give him a team-high 64 total. Lorenzo Alexander, for all his shortcomings in pass coverage, has been strong in run support and rushing the passer. He has 2 sacks, 3 forced fumbles, and 40 total tackles on the year; with Ramon Humber missing much of the second quarter of the season with a thumb injury, Alexander overtook him in solo tackles for the team lead. The real revelation, though, has been rookie Matt Milano. He stepped right in for Humber and the defense didn’t miss a beat. Milano has 14 total tackles on the year, but it was his 40-yard fumble return touchdown that sparked the Bills to a big blowout win over the Oakland Raiders two weeks ago. He also intercepted Jameis Winston in Buffalo’s victory over the Tampa Bay Buccaneers. Overall, the linebacking corps has been a pleasant surprise this season.

Secondary: B+

Buffalo is second in the NFL in interceptions, trailing only the Baltimore Ravens on the season. Micah Hyde, Buffalo’s starting free safety, leads the NFL with 5 picks on the season; the secondary has contributed 10 of the team’s 11 interceptions. Why only a “B+” in the second quarter, then? Too many yards allowed. Granted, some of the blame has to fall on the front-four for their inability to generat pressure on the quarterback; however, the Bills allowed over 300 passing yards in three consecutive games. After allowing 1 passing touchdown over the first 4 games, they allowed 6 passing touchdowns in the next 4 games. Tre’Davious White has been very good so far, but he has had a coupled of bad games (against the Cincinnati Bengals and then again against the Jets) that have reminded us that he is a rookie, even though his 14 pass breakups on the season is an incredible number. With E.J. Gaines spending much of this quarter on the sideline, opposing teams have picked on Shareece Wright, exposing Buffalo’s lack of cornerback depth. Interestingly enough, the safety depth has also been tested, with Jordan Poyer missing a start against the Raiders, but Trae Elston stepped in and was phenomenal, leading the Bills with 11 tackles and an interception in the contest. A healthy Gaines will go a long way towards re-solidifying this group, but it took a small step back in the season’s second quarter.

Defense Overall: B

They’re allowing opponents to convert 40% of third downs, the 13th-highest rate in the league. We saw what happens when they don’t force turnovers in Thursday’s beatdown courtesy of the Jets. Head coach Sean McDermott and defensive coordinator Leslie Frazier need to find a way to generate more pressure on opposing quarterbacks, because the caliber of signal callers that they face over the next four games is far greater than what they’ve seen so far. The slate includes dates with Drew Brees, Philip Rivers, Alex Smith, and Tom Brady.