Patriots D poor against 'power' running

In collecting some data for a story about how well Buffalo Bills nose tackle Kyle Williams is performing this year, Football Outsiders managing editor Bill Barnwell led me to some interesting run defense numbers.

Football Outsiders calculates "power success" against runs on third and fourth down when 2 yards or shorter is needed to move the chains or any down when a team needs 2 yards or shorter to reach the end zone.

While the Bills have the NFL's worst run defense, they rank 15th in power situations. Opponents are successful just 61 percent of the time.

By comparison, the vaunted New York Jets rank third in run defense (first in Football Outsiders' adjusted line yards metric), but 15th against power runs at 60 percent.

The Miami Dolphins also are at 60 percent, but they're ranked 14th because they've faced more attempts.

The New England Patriots, however, struggle in power situations. Opponents are successful 77 percent of the time, ranking the Patriots 28th in the league, a major reason why they own the NFL's worst defense when it comes to getting off the field. They rank 32nd in third-down efficiency and are tied for 28th on fourth downs.