(Written by kencraw)

Of all of the things I heard over the off-season, the one that gave me the most “instinctual” heart-burn, it has been the decision to return to the 4-3 defense from the 3-4. I think we all remember recent history, but for those who don’t, or perhaps to lay out how I think recent history went:

Starting in 2005 or so, spread offenses started to become all the rage (because they were working). The big thing they did was find a way for smaller teams to work around big defensive lines by going around them. They started developing key plays like the read-option where they could isolate one defensive end and take him out of the equation (either way he guessed, the play went the other way).

And as I said, it worked… almost too well.

But of course defensive coordinators aren’t going to stand still and just take a beating. They started developing new ideas. One of the first was the “Bend But Don’t Break” strategy, which relied on lot of zone coverage and spreading out the defense a bit. It worked to some degree, particularly when they’d force the spread offenses into a big loss every once in a while, breaking their rhythm and into more traditional passing situations on 3rd down where the big defensive linemen could go for broke after the QB. But it only worked so well and it left the defense on the field a lot giving up a lot of small gains that would take their toll in the 4th quarter.

The next stage of development started in the 2008-2009 time frame. (And to give credit to our former coaching staff of which I dare not speak, they were on the leading edge of this.) Defenses realized that by taking a defensive lineman off the field and replacing him with a linebacker they got a number of positive effects. First of all, there was more speed on the field to cover more territory. But just as important (and often overlooked) was the gap assignments of the defense were no longer as predictable to the offense. As a result, things like the read-option trap for the defense end was no longer so clear. Who’s the appropriate guy to read? The DE or the 4th/outside linebacker? It could change on each play depending on alignment.

And this new strategy worked! Looking at the teams who had defensive success against the best spread teams, most of them were 3-4 teams. And while the games of cat and mouse continue to the day, the playing field feels a lot more balanced.

So this 4-3 thing has to be a disaster in the making, right?

Frankly, it might be… but I’m also not so sure until I watch them on the field.

The reality is the line between a 3-4 and a 4-3 has blurred. If you have your outside linebacker up on the line with his hand on the ground pre-snap, how much different is that than a 4-3? If you replied with “speed”, then when your outside linebackers in the old 3-4 become DE’s in your new 4-3, how different is THAT?

The more I think about it, I guess to some degree 4-3 vs. 3-4 isn’t all that important. But I do think there are some concepts that have been integrated into the modern 3-4 offenses that are very important to success in today’s Pac-12. So if you’re going to run a 4-3, you need to make sure you incorporate these things.

So this post was a long way of saying here’s what I’m looking for out of the defense when they take the field:

• Do they occasionally drop linemen into coverage? One of the keys to the 3-4’s is that where the rush is coming from is very confusing to the QBs and the offensive linemen. You do that by bringing different linebackers at different times. And at some point, you bring so many linebackers that you need a lineman to get up out of his stance and cover the middle zone. This is even more true when 4 of your rushers (instead of 3) are “predictable rushers”.
• Are the outside linebackers lining up fairly widely? Remember in 2011 when USC beat the ever-loving-crud out of us? (Yeah, I’ve mostly blocked it out too, but dig deep, it’s in there somewhere.) One of the things I remembered was part of how they beat us was by placing the outside linebackers extremely widely. Whenever we went sideways, which we liked to do a lot with Maynard and co. that year, it was a disaster. It seems like the 4-3’s that are successful place their outside linebackers pretty wide (although I don’t think it has to be as wide as USC did that night).
• Where are the safeties playing? An alternative to the previous strategy is to bring the safeties up, on the outside. This has an upside of keeping the inside run support fairly strong with the outside linebackers able to collapse inside as needed. The downside of this strategy is that there are certain deeper passing routes that are harder to cover with the safeties out of their traditional positions. However, I think a fairly innovative defensive coordinator will be doing the same sort of “position swapping” (or maybe you could call it ‘creative zone coverages”) that we’re seeing today between the linemen and backers, but instead between the safeties and their fast linebackers. It’s something that will keep the QB REALLY off balance. (If I see this I’ll be very impressed, but will expect to see some growing pains.)
• How dominant are our ‘true’ linemen? I think the #1 key to the 4-3 is that by putting 4 big bodies up on the line you have the potential to be very disruptive right off the snap. But that’s the thing… they NEED to be disruptive. You can’t have a stalemate on the line. Back in the pre-spread days, stalemates on the line were often OK because on running plays the stalemate resulted in a minimal gain and passing plays could often be contained by good secondary coverage. These days, if you’re going to have big bodies on the line, they’d better be disruptive right off the snap (and BTW, I think we have the personnel for this).

So, is the 4-3 bad? Maybe, maybe not. But that’s what I’ll be looking for to find out.