The Bills switched up their defensive personnel on a drive-to-drive basis, which will be par for the course under defensive coordinator Mike Pettine this season.
After taking a second look at the game, we'll try to sort things out:
Pettine has historically leaned on defensive backs more than linebackers in his scheme. So while the Patriots only used four-receiver sets for five plays in the game, according to Patriots reporter Mike Reiss' tracking, Pettine gave Tom Brady and the Patriots a heavy dose of six- and seven-defensive back packages.
Undrafted rookie Nickell Robey was the fifth defensive back on the field and held his own in the slot. The Bills had Ron Brooks in this spot for almost the entire preseason, so while it was a risky move for the Bills to swap him out for a rookie, it paid dividends.
When the Bills went to six defensive backs (their "dime" package), they gave one of two looks: (1) safety Da'Norris Searcy would slide down into the box, helping to pick up receivers across the middle of the field, with Jim Leonhard taking his place in the back end, or (2) cornerback Ron Brooks would come in as an extra cornerback, with more edge responsibilities, with Searcy remaining in a deep zone.
When the Bills went to seven defensive backs, Leonhard slid down into the box, with Searcy remaining deep. It was the opposite look from the dime package.
The front seven in the base defense had one surprise: at linebacker, Arthur Moats stepped in place of Nigel Bradham for stretches, although there were some plays when Bradham was part of the base look.
The defensive front four -- Alex Carrington, Kyle Williams, Marcell Dareus, and Mario Williams -- was the same in both the base and nickel packages. In the dime, Jerry Hughes replaced Carrington to provide more pass rush. When the Bills went to seven defensive backs, it was Williams, Williams, and Hughes along the front.
Defensive lineman Alan Branch played 33 snaps, rotating in at all spots on the defensive line. It was impressive versatility by the 325-pound Branch, who was required to play several different techniques/gap assignments.
Looking forward, the Bills will be without Brooks for "some time," head coach Doug Marrone said, after Brooks fractured his foot in Sunday's game. The best bet is the Bills will stick to their two dime looks, with waiver-pickup Brandon Burton sliding in for Brooks when Leonhard isn't on the field.