MIAMI -- Statistically speaking, where has the Miami Dolphins' defense gone wrong in 2021?

During last season's 10-win campaign, Miami wasn't necessarily spectacular on paper. It ranked 20th in yards allowed per game (367.9) including 16th against the run (116.4) and 23rd against the pass (251.5).

The Dolphins bent plenty of times throughout the season, but ranked among the league's elite in critical situations. They owned the best third-down defense (31.2%), the seventh-best red zone defense (57.5%) and tied for the fifth-best scoring defense (21.1 points per game) in the NFL in 2020. Perhaps most importantly, they led the league in takeaways, with 29. So opposing offenses could pick up empty yards, they just weren't converting them into points or scoring opportunities.

The issue in 2021, however, is that the Dolphins' defense is bending and breaking.

Not only is it ranked 32nd, allowing a league-worst 414.9 yards per game, it is tied for 10th in takeaways (including 27th in interception rate), 31st in third-down defense and 14th in red zone defense. As a result, the Dolphins are allowing the second-most points per game (29.6) as they prepare to face the Buffalo Bills (4-2), who have outscored them 91-26 over their past two meetings.

Miami (1-6) has lost six straight entering Sunday's game in Buffalo (1 p.m. ET, CBS).

"I don't think you want to be the same thing over and over against people, so you try to change the picture," defensive coordinator Josh Boyer said. "Whether that's changing the front or changing the coverage, especially against a lot of the good quarterbacks that we face. We always try to apply pressure to them and apply pressure to the offensive line. I think a good mix of calls is always kind of what you're looking for."

Boyer's defense, which played Cover 3 zone at the eighth-highest rate in the NFL last season, has shifted toward a man-heavy coverage scheme, deploying Cover 1 on 43.1% of opponents' dropbacks -- the fourth-highest in the NFL.

The Dolphins are still blitzing, though at a slightly lower rate this season (32.6%, sixth in NFL) than they were in 2020 (38.9%, third), but have the third-lowest sack percentage in the league. Translation -- they're trying to apply that pressure Boyer mentioned but not finishing.

As Boyer puts it, this league figures you out before long and it's up to the Dolphins to make adjustments in response.

"Obviously, I don't think at any phase is exactly where we want with the consistency that we want -- whether you are talking run defense, pass rush or pass coverage," he said. "Again, I think that goes into we have to coach it better and keep a variety of things to try to put our players in a better position to succeed. The other thing is when you do something over and over again, teams prepare for it and they have a lot of plans for it.

"It's not one of those things that you can consistently year after year do the same thing over and over again."

However, there are some reasons for optimism in regard to Miami's defense. It's held its past two opponents under 100 rushing yards after failing to hold any of its previous five opponents under even 120 rushing yards. And against the Atlanta Falcons in Week 7, the Dolphins created two turnovers in the fourth quarter when they erased a 13-point deficit and took the lead in the final minutes.

But they also allowed completions of 23 and 28 yards to rookie tight end Kyle Pitts on the first two plays of Atlanta's game-winning drive, putting their opponent in a position to run out the final two minutes before sealing the game with a field goal. Sunday marked Miami's third loss this season on a last-second field goal, which coach Brian Flores said serves as a lesson for how slim the margin for error is in the NFL.

"When it comes down to a field goal at the end, there's always one or two plays that could have turned it and could have been the difference," he said. "We understand that. We just have to make more plays throughout the game so it doesn't get to that point.

"It's been disappointing. But as far as the psyche of the team, I've said this all year that this is a resilient group. This isn't an effort issue. This isn't a desire issue. This is just a situation right now where we're just not doing enough to pull these games out."

The playoffs are out of the question for Miami, barring an unprecedented run to end the season, but if the team wants to salvage some pride on that side of the ball over the next 10 weeks, it must get back to what it did best last season -- bending without breaking.