Patriots' D not as bad as numbers say

The New England Patriots made history in the first four weeks of the 2011 season. Or perhaps more aptly, history was made against them.

The Patriots have allowed 1,910 yards through four games. That's the most in NFL history through a team's first four games, according to the Elias Sports Bureau, breaking a mark of 1,894 allowed by the 2005 San Francisco 49ers.

Before that you had the 1950 Baltimore Colts, who allowed 1,855 through four games and are still the only team in NFL history to allow over 450 yards per game over the course of a season.

That is, unless the Patriots do it. They are currently giving up 477.5 yards per game.

Those 1,910 yards are 103 more than the Patriots have allowed in any four-game span in their history, according to Elias. The previous high of 1,797 yards allowed came over the course of the final four weeks of the 1986 regular season.

No matter the context, the Patriots are giving up yards at an alarming rate. Masked by a prolific offense, the defense remains a clear question moving forward.

Yet, despite all those yards, the Patriots are still 3-1. As long as they keep winning, is there really anything to worry about?

Compare the current success to the other teams that opened a season this way. That 2005 49ers team started 1-3. The 1950 Colts were winless through four games.

Indeed, the Patriots' own history suggests that continued success while allowing this many yards is unsustainable.

In all three of its wins, New England has allowed over 450 total yards. The lone loss to the Buffalo Bills happens to be the only game in which the Patriots haven't allowed 450 yards (448).

Entering this season, the Patriots were 6-32 all-time when allowing 450 or more yards. This season, they are 3-0.

The 504 yards for the Oakland Raiders last week were the most the Patriots ever allowed in a win. That broke a mark set in Week 1 against the Dolphins (488 yards). All three of New England's wins rank among the top five in yardage allowed in a victory.

The biggest issue has been pass defense, where the Patriots have made Chad Henne look like Dan Marino and allowed Ryan Fitzpatrick to do a Jim Kelly impersonation.

New England is allowing 368.8 passing yards per game, 33 more than the next worst team. That's more than the total yards per game allowed by 20 teams.

Historically, the significance of these numbers is somewhat mitigated by a league-wide rise in passing yards. According to Elias, the first four weeks of the 2011 season now comprise the top four passing weeks in NFL history. Yet, that doesn't quite get the Patriots off the hook.

It's once again easy to point to a lackluster pass rush, which has combined for only six sacks. Andre Carter, Shawn Ellis and Albert Haynesworth were expected to add more push from the defensive line, but they've accounted for only half a sack.

Just 3.4 percent of opposing passing plays have ended with a sack. Only the Bills (2.6 percent) have been worse. Yet, there's no great urgency to increase the pressure. The Patriots bring more than four pass rushers only 18.0 percent of the time, the third lowest rate in the league.

Some blame can also be pointed at the secondary, where the Patriots have been susceptible to big plays. They've allowed 33 plays of 20 or more yards, most in the NFL and nearly twice the NFL average (17). Opposing quarterbacks are 11 for 22 for 354 yards on passes thrown over 20 yards.

It sounds bad when pundits mention that the Patriots rank last in the NFL in total defense. Yet, their success underscores the flaw in measuring effectiveness in yards.

Consider that the Patriots 32nd-ranked defense is allowing 24.5 points per game, tied for 20th in the NFL. That puts them just ahead of the Dallas Cowboys, who are allowing 25.3 PPG. The Cowboys have the NFL's fourth-ranked defense, allowing 291.8 yards per game (or almost 200 fewer than New England).

So how have the Patriots succeeded despite all of the yards accumulated by opponents?

Considering the number of yards they've allowed, the Patriots defense has been quite effective at keeping points off the board.

That starts with field position, a small, but not insignificant reason opponents rack up yards. The average starting field position against the Patriots is around the 21 yard line, the best in the NFL. That's about seven yards shy of the league average (28.2). The difference may seem small, but multiplied over the course of a game, it could account for 50-75 more yards that New England can afford to give up.

Another key factor is when the yards were allowed. Of the 1,475 passing yards given up by the Patriots, 795 came when they were leading by more than a touchdown. That includes 277 passing yards allowed when up by 15 or more points. In other words, much of the damage done against New England came when the Patriots could afford it.

With all of those yards, the situation could be far worse. "Bend but don't break" is an apt description (sound familiar?). In some cases, the Patriots have bent over backwards. But the defense has also stepped up in key situations.

New England has forced three red zone turnovers, which leads the NFL. The Patriots could be in a far different place had those drives ended in touchdowns.

The much-maligned pass defense has excelled in the red zone. Total QBR provides a comprehensive measure of a quarterback's effectiveness on a scale of 0 to 100.

Outside the red zone, quarterbacks have combined for an 82.8 QBR against the Patriots, highest in the NFL. But in the red zone, they've thrown three interceptions and been sacked twice against New England. That's led to a 3.0 QBR against the Patriots in the red zone, the lowest of any pass defense.

Jeremy Lundblad is a senior researcher with ESPN Stats & Information. He provides statistical analysis for ESPNBoston.com.