Methodology (read if you want to know the details about my analysis)
- I ignored drives when NE was attempting to run out the clock, or where there wasn't enough time for anything to really happen.
- I ignored points that the NE defense scored against anyone else's offense.
- I looked for drives in which a Buffalo turnover led to a NE 3-and-out followed by a field goal. Clearly that field goal would have been the fault of our offense, not our defense. There were no such instances. There was a case when the NE offense used a Bills' turnover to drive 27 yards for a TD. I treated this as a normal drive, because our defense should have stopped this TD, and because this is how I treated the other teams in the analysis.
- I looked at what the NE offense did on a per-drive basis. There were two reasons for this: 1) if your own offense is good at chewing up the clock, the other team's offense will have fewer possessions. All else being equal, your defense will therefore allow fewer yards and fewer points. 2) A defense that allows a 10 minute TD drive has done more damage than a defense that allows a quick strike for a TD. Yet the first defense will allow fewer points and yards throughout the game, because the other team's success in chewing up the clock will lead to fewer possessions for both teams. What really matters is the average number of points your own offense must score on each drive in order to win. The higher the number, the more pressure your defense is putting on the offense. The worst-case scenario would clearly be a defense that allowed a TD every drive, because then your offense would have to be perfect to win.
NE's games in 2004 were as follows:
Indy
Ariz
Buf
Miami
Seattle
Jets
Pitt
St. Louis
Buf
KC
Balt
Cle
Cinn
Miami
Jets
San Fran
There are more bad defensive teams on this list (Indy, Ariz, Seattle, St. Louis, etc.) than good ones. The Patriots' best offensive performance came against St. Louis. In that game, they scored on 80% of their possessions, averaging 4.00 points per possession. The worst game for the Patriots was against Baltimore; when they scored on 33% of their possessions, and gained an average of just 1.33 points per possession.
For the year, an average of 15% of the Patriots' drives ended because of a turnover (18% if you count turnovers on downs). Against the Bills, 11% of the Patriots' drives ended because of turnovers.
There were only four games in which the Patriots' offense had more success (either in points per drive or percentage of drives where points were scored) than its average success against the Bills. These games were against the following teams:
- Indy
- Seattle
- St. Louis
- Cinn
Even Cleveland's defense did a better job against the Patriots than our defense did. The Browns allowed the Patriots to score on 40% of their drives, and average 2.55 points per possession. The Arizona Cardinals allowed the Patriots to score on 50% of their drives, and to gain an average of 2.3 points per possession.