The first article generated good discussion. Not just "Nic, that's great" but "why does this matter in a video game" level of discussion. Starting with "why" is the sign of someone who does critical thinking for themselves, rather than look around and follow someone who is successful.
The 3-4 is not quite as old as the 4-3, and no where near as prolific but it is the weapon of choice for some of the best pass rushers the game has ever seen.
Once again, we'll study the basics, but in this article we'll be able to go a bit further into variants of this defense. The defensive line one that has been pretty consistent historically.
The NT is probably the favorite run stopper of even the most casual fans. 350+ in some cases, this is the position fans envision Andre the Giant playing. Ted Washington, one of the first prototypes that comes to mind was 6'5" and 375 lbs in his prime. If it isn't obvious already, this guy needs to move the pile, stand up blockers, and club a RB with the broken bodies of interior offensive linemen.
Some of you have done the math and realized that 3 down linemen may just be a weak formation against the run. You are correct. This is part of the reason that the 3-4 is not widely used. But to combat this, most good 3-4 defenses make their two DE's 280-310 lbs. These guys are likely to be tweeners between strong-side end and a 3-tech in a 4-3, but sometimes are just a pure DT type player. These DEs are both 2-gap specialists, although often one of them will be at least an ok pass rusher. After all, you don't want to put 3 players on the field that can't influence the pocket at all. One of the best recent DE's was Richard Seymour, a guy who would have been a killer DT against the run and rushing the passer. He could rush the passer and stop the run very well, and was one of the keys to a truly elite front for the Patriots and allowed them to plug and play behind him. A luxury they no longer have.
Yes, JJ Watt is a 3-4 DE. But he is in Wade Phillips defense which is unique. This 3-4 is run much more like a 4-3, with a lot of one-gap responsibilities. In my inner dialogue I call it an "attack 3-4" where it often resembles a 5-2 or some forms of the 46 defense where the OL is overloaded with penetrating defenders. The Texans put a ton of pressure on their secondary to win in man coverage, and injuries to some of their best players in the past couple of seasons kept this from being the top 3 defense it was on track to be.
Part of the reason the 3-4 never dies has to do with talent acquisition. There are a lot of 235-265 lb pass rushers that can't be elite 4-3 DEs. They'd get dominated. The Seahawks defense uses a single DE at the 255 lb range to act like a 3-4 OLB, but the elite 4-3 DEs are normally a 265 lb freak or a 275 lb good/great player. That earns a lot of money.
So in the 4-3, those smaller college pass rushers turn into nickel/dime rushers. But the 3-4 has a home for them. OLB. Furthermore, those guys play standing up, and can move up and down the line while the OL & TEs are stuck to the ground, gnashing their teeth. The OLB position is the money position in the 3-4 defense. Lawrence Taylor, Derrick Thomas, Shawn Merriman, and many other fearsome pass rushers have dominated with the space to focus on pass rushing lanes and the advantage they get from the defense's structural mobility.
Of course, the most well-known advantage is that the 4th and/or 5th pass rusher is disguised extremely well. With 4 linebackers, any one of them can be the 4th rusher, making overload blitzes the primary strategic strength of a 3-4. The OLB also will have pass coverage responsibilities, although often they are only used in the flats. Great pass rushers are rarely used as a pass coverage guy.
Some defenses will have an OLB that is much better at coverage than the other, and will shift their percentages to take advantage of that, the same with those who are the best pass rushers.
The ILBs (two players sharing the middle can't be called middle (
) have surprisingly different roles in most 3-4 defenses. One guy will be focused on the pass and flowing to the sidelines. Often this is a MLB that would normally be too small/weak for a 4-3 defense but is great at pass coverage. That speed is also used on surprise blitzes that the offense doesn't see coming. The other guy is often the biggest linebacker on the team, a run-oriented guy that is sort of the FB of the defense. He'll be the one linebacker that is expected to stand up an OG in the hole, freeing the other linebackers to close to the contained HB. Traditionally, this guy will be the difference between being gauged in the run game and being good.
These are linebacker positions, so there is a ton of variance available. And of course, the traditional do-all, fast/big 4-3 star has a place at MLB or OLB here. But the 3-4 traditionally is built from the very skilled leftovers from the 4-3, guys who are only part-timers in the 4-3 defense.
Integration was mostly covered, but the 3-4 has known weaknesses that are combatted mostly through personnel selection. That said, in Madden one of the most impressive defenses I've ever seen was the Colts 3-4 in the first two seasons of the RZL. They added Terrell Suggs as an OLB while playing Mathis and Freeney at DE with merely one run-stopper at NT. Their amazing offensive production did integrate well with this defense's strength, but at the same time the defense gave the offense extra possessions as well. They played the most pure penetration scheme I've seen and were hugely successful.
More real-life are the current Texans, with OLBs and 3-4 DEs that rush the QB. This is like the 46 of 3-4s, with the emphasis being on getting to the QB quickly and letting the secondary cover for a short time.
Another variation would be the Patriots 3-4 with an emphasis on dropping 8 and only rushing 3. They worked hard to acquire OLBs that can cover well. On occasion I've used a (inner dialogue again) "passive 3-4" with pass coverage/speed from all 4 linebacker spots and low aggression to emphasize coverage. Finally, there was one RZL game where Ricky Lung put 4-3 DEs at OLB playing a 5 DL scheme with his 3-4 to stop the run-heavy game I was running. It worked outstandingly against me, at a time when I had the best OL (before the Saints got even better) in the game and knew I could beat him on the ground.
In conclusion, understanding the strengths and weaknesses of your formation help you honestly evaluate your defense in the short and long term. As the first step for a GM, you can predict how successful your front 7 will be against the run, and against the pass. You can leave it unbalanced to take advantage of what is easy to get on the market (like the 3-4 in real life) or to force teams to do what you want. And when something breaks, you can easily troubleshoot it based simply on your players, what strengths they have, and what you might need to add to the stew to give you the advantage.