Dallas Cowboys: The Flex Defense VS The 4-0 Defense

Source:The Logical Cowboy with a look at Tom Landry's 4-0 defense.

"A Deep Look into Tom Landry's 40 Defense of the 80s" 

From The Logical Cowboy

If Tom Landry had a basic defense philosophy and strategy as a defense head coach, which is how he started out as a defender when he played and as a defense coordinator with the New York Giants, before he became head coach of the expansion Cowboys in 1960, it was to make opposing offenses one-dimensional. His goal was to force the opposing offenses to throw the football all the time against his pass rushers and secondary, by taking away the other team's running game.  

Pre-1984 and starting in the mid 1960s, the base defense of the Cowboys was the flex defense: 

"The Dallas Morning News has a cute article, about how the first defensive call by Rob Ryan on the first defensive play of the first preseason game of Dallas in 2011 was the 43 Flex. I recall watching that play and thinking “psycho front”. And yes, Ryan has 4 players along the line of scrimmage and 3 players at linebacker depth, but what we’re going to do in this article is talk about about Tom Landry’s first two defenses, the 43 inside and 43 outside, and how they then morphed into the flex, to better use the talents of their All-Pro defensive tackle, Bob Lilly.

The ideas for the Flex came about after Bob Lilly’s move from left defensive end to right tackle. Dick Nolan describes it as one half of  the line playing a 43 inside, one half playing a 43 outside. To note, the  tackles in the inside/outside are flexed. In Tom Landry’s Flex, however, it depended on which side of the offense was “strong”, or likely to be  the side players would run to. Bob, in Peter Golenbock’s book, describes it as follows:

If I were on the weak side, I’d be head-up with the guard, right on the line of scrimmage, whereas the tackle on the other side would be three feet back. George Andrie would be right over the tackle and instead of being on his outside shoulder, he’d be head-up, three feet back. He would be keying my guard. I also keyed my guard." 

From Code & Football

The Cowboys pre-1984, would be in the flex defense on 1st down, against opposing offenses. It was somewhat weak against the pass, because the DT's would intentionally line up off the line of scrimmage, so they could react how the other team is trying to run the ball or what type of passing play they would be running. Instead of just attacking the other team's offense, regardless of what play they might run on 1st and expecting that you defense and you personal is good enough to stop what the opposing offense is truing to do to you. The flex defense was reactive, instead of proactive against opposing offenses. 

Well, in 1978, the NFL changed its pass blocking and defense coverage rule, which more than anything as revolutionized what is now the modern NFL and has made NFL offense balanced. Pre-1978, most NFL teams probably ran the ball 60% of the time and only the good teams completed even more than 55% of their passes and perhaps just 50%, because offensive linemen weren't allowed to extend their arms when blocking and defenders could essentially tackler receivers even before they got off the line of scrimmage, let alone before they got the ball. With the new blocking rules and illegal contact rule, NFL offense became balanced. Which meant the flex was no longer dominant against the run, but still effective.

Like with all great head coaches, when the league adapts against you, you either successfully adapt yourself, or you go out of business. Which is why Tom Landry went with 4-0 defense full-time in 1984 or so, to bring more pressure against opposing team's QB's. This is the 4-0 defense.

"The other basic Dallas defenses, beyond the 4-3 flex:

The 4-0, wherein Meg, middle linebacker Lee Roy Jordan, is removed for a defensive back, such as Barnes.

The 4-0, 6, whereupon Sarah (the strongside linebacker) is also removed and safety Randy Hughes takes his place. Barnes and Hughes are thus the fifth and sixth backs. The Cowboys had never employed six backs in a formation before last season." 

From D- Magazine

What made the Cowboys 4-0 unique, was while the Chicago Bears were bringing everybody, especially their linebackers when they rushed the QB, while the Washington Redskins were stunting and red dogging with their defensive lineman and linebackers, the Cowboys would go with their 4-0. 

The Cowboys would still have their 4 lineman in to attack the QB, but would have 5 defensive backs lined up on the line of scrimmage. Now, if you know the other team is not going to run the ball and you have excellent cover corners, and of course you have excellent pass rushers up front, the 4-0 can be a great defense against the pass, because you are basically leaving opposing offenses o-lines alone to block all your pass rushers, unless they go with max protection. 

But, if you don't get to the QB, now your corners are vulnerable to big pass plays. It's the whole Las Vegas gamble, unless you know the other team's offense so well and know you defense is up to this challenge.

I think what made the Cowboys defense special in the 1970s and even in the 1980s, when the Cowboys were no longer dominant even in the NFC East, let alone the NFC, and the entire NFL, was that they could get to the QB with just their 4 down lineman. They would also take away you're 1st down run with just their down lineman. And maybe they would red dog linebacker Tom Henderson, just to give opposing QB's and offensive coordinators something else to think about. 

When you have Ed Jones, Harvey Marin, Randy White, Jethro Pugh, and later Jim Jeffcoat up front, you shouldn't have to blitz or even red dog a lot, to get to the QB. But Tom Landry was always thinking and looking for new ways to make the Cowboys even better and be able to adapt to the times as they were changing in the NFL. 

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