Jermaine Cunningham made an impact on defense rushing Bills quarterback Ryan Fitzpatrick. (Matthew J. Lee / Globe Staff)

By Zuri Berry, Boston.com Staff

FOXBOROUGH -- Whether it is the bend-but-don't-break defense that has you up in arms, or the resilience of those entrusted with protecting the end zone for the Patriots that sent a chill up your spine, Sunday's 37-31 win over the Buffalo Bills is a matter of perception.

For both the pessimist and optimist alike, there is something in Sunday's game that speaks to your gridiron view. Here are some thoughts on Sunday's game that speaks to both.

1) Devin McCourty happens to be a twin with two faces -- There's Devin McCourty the beatable and inconsistent cornerback, and then there's Devin McCourty the let-no-man-cross-his-face safety who suddenly has trouble tackling. Against the Bills, we watched as McCourty missed his fair share of tackles (three to my count) before he made a splash with a forced fumble in the fourth quarter on Fred Jackson at the goal line. And in the end, he was the man standing in the end zone playing catch with Bills quarterback Ryan Fitzpatrick. All he had to do was make a play. For the Patriots, that can be considered good enough. He has ball skills and he's not afraid to use them. There's no shame in players that make plays at opportune times. If anything, it's the Bills' fault for making players like McCourty look better than they are.

2) Is the defense getting worse? -- Fitzpatrick passed for 337 yards and two touchdowns. We already know that secondary is not the Patriots' strength. Instead, Patriots fans have felt all warm and fuzzy inside knowing that the team's run defense was one of the best in the league. The Patriots were holding opponents to 88.6 yards per game, good for eighth best in the NFL. That ranking will surely take a hit come Tuesday. Fred Jackson and C.J. Spiller combined for 150 yards rushing and Fitzpatrick chipped in 12 more as the Patriots gave up a season-high 162 yards on the ground. With a healthy front seven, one has to wonder if the troubles of the secondary are affecting the team's ability to defend the run. We could chalk it up to the two explosive running backs the Patriots faced Sunday, but that doesn't hold up when compared to the team's past performance against some of the league's top running backs. Pick a running back, any running back, and each one was limited by the Patriots' defense. Some more than others. Chris Johnson was bottled up for 4 yards in Week 1. Willis McGahee finished with 51; Marshawn Lynch had 41 yards and Steven Jackson tallied 23. Sunday's effort by the Bills on the ground doesn't speak well for the Patriots defense or its future prospects, especially considering the elite running backs still on the schedule.

3) A change in the defense causes a change in performance? -- Jermaine Cunningham's 6-yard sack on Fitzpatrick in the third quarter was his second full sack of the season. His last came against the Tennessee Titans in Week 1. He also forced a holding call, recovered a fumble, and had a tackle for a loss, making Sunday's game another successful day at the office for the third-year pro. But the hybrid defensive end and linebacker has found himself lining up over guards more and more with Sunday's game as no exception. It's a pretty significant change from the purely outside pass rusher he's been known to be. Between Cunningham, Chandler Jones, and Rob Ninkovich, the Patriots have good ends that make things difficult on less athletic tackles. However, this wrinkle has Cunningham working as a backup for Kyle Love in sub packages and may have already backfired. Again, the team gave up 162 yards rushing against the Bills and a lot of that came when the team was in those sub packages. At 255 pounds, having Cunningham go toe-to-toe with interior linemen doesn't appear to be the best use of his talent.

4) Danny Woodhead must love the Bills -- Woodhead ripped off a 15-yard touchdown when no one on the Bills was looking and then weaved his way to the end zone on an 18-yard touchdown reception that crossed the goal line by a whisker. The last time the Patriots played the Bills in Week 4, he caught a 17-yard touchdown pass where he zigzagged his way through traffic before getting into the end zone. Three of his four season touchdowns are against the Bills. And to top it off, Sunday's two-touchdown effort was the first multiple touchdown game of his career.

"Now that it's mentioned, I guess, yeah," said Woodhead. "But that's not something I'm too concerned with. The team comes so far before myself and it's the win that matters. It's not myself getting two touchdowns."

5) Who's up and who's down in the Patriots secondary -- Steve Gregory finally returned to the Patriots' lineup after missing four games due to a hip injury. He played the whole game. But what was interesting was whose place he took in the starting lineup. Rookie Tavon Wilson, who had started in place of Gregory, was removed midway through the first quarter as the team opted to pair Gregory with Devin McCourty at safety. Alfonzo Dennard came in as the team's left cornerback, opposite Kyle Arrington. In nickel and dime situations, Wilson played sparingly, giving way to Marquice Cole. It's telling for a guy who has been picked on quite a bit. Despite giving great run support, Wilson has been a liability on deep passes. When Patrick Chung returns, I'm sure the rotation will change again with McCourty moving back to cornerback. Despite all the changes, there's been no improvement on performance. If the team is ever fully healthy, it might be a good idea to re-think strategy over personnel.