Buffalo Rumblings
One of the most distinct themes from the Buffalo Bills 2025 season was the regularly striking difference in the club’s defense in the first half of games compared to the second half of games.
The Bills were simultaneously disappointing out of the gates in contests and outrageously good at making second-half adjustments in the locker room.
While those second-half adjustments were encouraging, they were often desperately needed. An under-discussed priority for Buffalo’s new defensive coordinator Jim Leonhard is starting faster so the Bills don’t need seismic improvements after halftime to stay in games late.
Said third and fourth quarter adjustments were across-the-board improvements in essentially every classic and advanced metric for the Bills defense.
Let’s start with a look at the traditional metrics (regular season):
Data courtesy of SumerSports.com
Fewer plays allowed — more punts, fewer sustained drives — significantly fewer yards, and that yards-per-play difference is massive. For perspective, that 5.75 yards-per-drive allowed in the first half would’ve placed between the Baltimore Ravens and Chicago Bears a season ago (8th and 9th best in the NFL, respectively).
The 5.15 yards-per-play average would’ve ranked between the Arizona Cardinals and Houston Texans (21st and 22nd, respectively).
As a pass defense, the Bills went from allowing 5.97 yards per pass in the first half of games, which would’ve ranked between 4th and 5th-worst — to 5.59 per pass in the second half (between 22nd and 23rd).
As for the heavily criticized run defense, in yards-per-carry surrendered, Buffalo’s first-half efforts would’ve been the worst in the NFL by a wide margin (5.53 vs. 5.3 as actual full-game worst, Giants). Its second-half efforts would’ve ranked the Bills run defense between the 8th and 9th worst in the NFL.
How about in the sacks and turnover departments?
It doesn’t matter which metric you pinpoint — the Bills were noticeably worse in the first two quarters of games during the 2025 regular season than they were in the second half of contests.
And if advanced stats — we can call them analytics — are your thing:
Ready for the context here? And, remember, with EPA for defenses, a negative number is better.
That 0.061 Expected Points Added Per Play allowed by the Bills defense in the first half of games last season was slightly worse than the Detroit Lions offense, which had the 8th-best EPA per play in football a year ago.
The second half defense morphed the opposing offense into somewhere between the Houston Texans and Arizona Cardinals offense.
The same theme bore out in Buffalo’s two playoff games last January. The team allowed 1.12 fewer yards per play — an enormous dip — which included 6.83 yards per rush surrendered in the first half against the Jacksonville Jaguars and Denver Broncos compared to 3.05 yards per rush in the second half of those games.
Of course, these numbers do speak to the resiliency of the Sean McDermott defense, particularly last season. It was an imperfect unit that somehow summoned superpowers after halftime following typically...
