By Mark Sandritter
Cold, Hard Football Facts taper of tales
Strategy and adjustments are an integral part of the NFL, with teams constantly altering philosophies in hopes of gaining a competitive edge.
Successes by one team are often duplicated by others, resulting in trends throughout NFL history. The evolution of the 3-4 defense provides a perfect case study.
The 3-4 is particularly relevant today with the two leading practitioners of the 3-4, New England head coach Bill Belichick and Pittsburgh defensive coordinator Dick Lebeau, squaring off in a huge AFC battle. Remember, Pittsburgh head coach Mike Tomlin was a 4-3 man but, after taking over the job earlier this year, left the 3-4 intact under Lebeau.
The modern 3-4 came of age in the early 1980s as a response to the dramatic increase in offense that came about with the end of the Dead Ball Era in 1977 and the rise of the Live Ball Era in 1978. But the 3-4 declined in the 1990s, only to see a renaissance here in 21st century, spurred in large part by its primary practitioner, Belichick.
Of the seven NFL teams that primarily employ a 3-4, three are the direct result of Belichick's influence: his Patriots, of course, along with the Jets and Browns, both of whom are coached by former defensive coordinators under Belichick. In addition to Pittsburgh, the NFL's other 3-4 teams are San Francisco, Dallas and San Diego.
But just about every NFL team, with the notable exception of long-time 4-3 practitioners Washington and Chicago, have used the 3-4 at one time or another. And, of course, in this day and age of zone blitzes and situation substitution, defensive formations on every team often take on a different look with each play.
In any instance, the ebb and flow of the 3-4 vs. the older, more widely employed 4-3, led us to a question: which defense is truly the best?
Although less than a quarter of NFL teams currently use the 3-4 defense, its success is still evident by the fact four of the top ten defenses from 2006 used the 3-4. Still, a number of teams have recently reverted back to a 4-3 defense diminishing the trend and adding speculation to the question of defensive supremacy. To answer the question the Cold, Hard Football Facts find some good sod and dig into the trenches for an answer.
TALE o' the TAPE: 4-3 vs. 3-4
No. of teams that
2007 win percentage
2007 points per game allowed
2007 yards per game allowed
2007 pass yards per game
2007 rush yards per game
2007 yards per play
2007 turnovers per game
2007 sacks per game
2007 completion percentage
2007 quarterback rating
2007 red zone defense
2007 first downs per game
2007 top 10 ranked defense
2006 top 10 ranked defense
2006 playoff teams
Big Play Index plays allowed
Super Bowl winners – last 10 yrs
Top ranked defense – last 10 yrs
Playoff appearances – last 5 yrs
1. 2007 is the year of the 3-4
As recently as 2001 the Steelers and Patriots were the only NFL teams using the 3-4 defense. Six years later seven teams use the 3-4 and although the numbers have been higher, team success may be at an all time high. If the season ended today five of the seven 3-4 teams would make the playoffs, with the Patriots and Cowboys billed as conference favorites.
For a comparison of success look no further than the win percentage of the 4-3 and 3-4 teams. Currently 3-4 teams have a .610 winning percentage, nearly 150 percentage points higher than the 4-3 teams.
Both of the 3-4 teams not contending in 2007 are in the early stages of transforming from the 4-3 with both the Jets and 49ers switching to the 3-4 full time in 2007.
2. But the 4-3 still dominates the league
Despite the recent Super Bowl success of Pittsburgh and New England, the 4-3 defense still dominates the league both in numbers and playoff victories. Seven of the last 10 Super Bowl winners used the 4-3 defense with the popular "Tampa 2" accumulating as many Lombardi trophies as the 3-4.
Of course, the limited number of 3-4 teams tells us that they were winning a relatively large number of Super Bowls.
The real measure of success lies in playoff appearances. Over the last five seasons, including the time of 3-4 revival, 4-3 teams made the playoffs five times more often than 3-4 teams.
Recently 4-3 teams have had success in pure numbers but also at the highest levels. Only three teams, New England, Seattle and Indianapolis, have qualified for the playoffs in each of the last three seasons, with both the Colts and Seahawks running the 4-3 defense.
Even New England, the most successful franchise in the modern era, won the 2001 Super Bowl while primarily using the 4-3 defense.
3. Statistically it's about even
Despite a large disparity in team success, the differences between the defenses statistically is lower than Eli Manning's passer rating. While the 3-4 holds a slight edge in almost all of the major defensive categories, the biggest separation is in red zone defense where the 4-3 holds a marginal edge in terms of touchdowns allowed.
In fact, the two defenses are almost identical in points per game, yards per play, rush yards per game and turnovers per game. Behind Pittsburgh's reputation as a run-stuffing defense which is known for blitzing the quarterback it is often assumed the 3-4 defense tallies more sacks and less rushing yards. With rush yards per game separated by a tenth of a yard and sacks by two tenths there could not be a larger misconception.
In fact the Seahawks, a team which has not used the 3-4 defense primarily since 1989, have ranked in the top six in the league in sacks each of the past three seasons including leading the league in 2005.
4.  The 3-4 takes time
While teams using the 3-4 are currently thriving, the struggles of teams switching to the 3-4 shows that it takes time to learn it and succeed with it. Not only do teams need a combination of versatile linebackers and quality defensive linemen, but coaching also plays a key role.
As we noted, three of seven 3-4 teams are the direct result of the influence of Belichick, who also used the 3-4 with great defense as the defensive coordinator of the Giants back in the 1980s. The Steelers continue to use the 3-4 primarily because of Lebeau. And two of the other 3-4 teams, also bear the imprint of a single coach, Wade Phillips, who employs it in Dallas and used it last year with San Diego (which continues to use it today).
At the same time a good offense can help speed up the process. The Browns, a previously dismal offensive and defensive team, are now poised to make the playoffs despite ranking near the bottom in many defensive categories.
The Bottom Line
The statistical similarities between the 4-3 and 3-4 defenses does little to solve the question of the best philosophy. Instead, a closer look shows the common thought of "defense wins championships" may prove to be wrong. The five 3-4 teams finding success in 2007 are all doing so with a productive offense while the Jets and 49ers are two of the worst defensive teams in the league.
The Browns and Jets have the 32nd- and 30th-ranked defenses but their difference in success can be directly related to offense. Even New England's rise to almost unbeatable status can be attributed to offense.
The Patriots ranked 11th in offense and 6th in defense in 2006, while compiling a 12-4 record. In 2007, the Patriots rank 3rd in defense but 1st in offense while already matching their 2006 win total.
In a league of fleeting trends, one of the most enduring institutions is the "what have you done for me lately" concept.
So with recent success the only most obvious factor in its favor, the 3-4 defense gets the nod over the 4-3 based upon the success of its teams here in 2007.