Over the past year, we've been wringing our hands over the Tampa Bay Buccaneers offensive line. And I'm still concerned with the state of the center of the Bucs' offense. If Carl Nicks can't start, they have a serious problem -- that probably means moving Jamon Meredith to left guard, and starting someone who either lacks talent (Oniel Cousins, Patrick Omameh), or lacks technique (Kadeem Edwards) at right guard. That's a recipe for disaster. 

Recently, I've seen some suggestions that the Bucs' (presumed) zone blocking scheme will mitigate those issues. However, we don't actually know what the Buccaneers plan to do with their offensive line. Judging by the players they've brought in and Jeff Tedford's history, the Buccaneers are likely to run a diverse scheme with a lot of movement. And to some extent, they're likely to base some of that on zone blocking principles.

But the idea that such a scheme means the Bucs can get away with sub-par offensive linemen and still get production is based on a few misunderstandings. Let's dig into what the "zone blocking" concept actually means.

Alex Gibbs' Outside Zone

When people talk about "zone-blocking schemes", they tend to mean the old Mike Shanahan Denver Broncos and their use of the outside zone/stretch play. It was perfect for them: it allowed them to propel late-round running backs to temporary stardom (most notably Terrell Davis). It's a very good scheme, and it can let you get away with undersized, more athletic offensive linemen. Not worse linemen, note, just a different type of lineman. Alex Gibbs, the offensive line coach for those Broncos, was the man who perfected this style of play. This is what it looks like 

if the Bucs were running this scheme, there would probably be less need to worry about the offensive line. Unfortunately, this is probably not what the Bucs are going to do. 

The Gibbs zone scheme is based on the repeated execution of one play, and one play only: outside zone. That one play creates a horizontal stretch across the defense, if executed perfectly. And to do that at a high level with sub-par personnel, you need to rep that one play over. and over. and over again. To the exclusion of nearly everything else.

Ben Muth explained this perfectly in his breakdown of the outside zone. 

This type of combination blocking takes a ton of practice time to pull off in game situations. If you want to run the zone stretch -- and I mean really run it worth a crap -- you probably need to devote around 65 percent of your individual offensive line practice time and 70 percent of your scripted runs in team drills to it. It’s a huge time investment.

Unless Jeff Tedford and George Warhop depart radically from what they've done in the past, this is not what they are going to do. They have run diverse offensive schemes, with a lot of movement that put great stress on the offensive line. Simply put: they have not run Alex Gibbs' outside zone scheme. 

Zone blocking principles

So what about the fact that we keep hearing that the Buccaneers are likely to base their offense on zone blocking principles? Well, that's true, to an extent. If you look at Jeff Tedford's 2004 playbook, you'll see a lot of zone blocking ideas. But zone blocking principles are not the same thing as the outside zone. 

Zone blocking is nothing more than asking your offensive linemen to block a specific area, rather than a specific player. It is no different than zone defense, whether in football or basketball, but applied to the offensive line. The outside zone is just one very specific implementation of a zone blocking scheme, and a very limited implementation at that. 

Every NFL team runs zone blocking schemes to some extent. Almost all NFL pass-blocking schemes contain zone elements, or defenses would simply run stunts every play and defeat offensive lines quite easily. Whenever you see two offensive linemen pass off pass-rushers between them, that's a zone concept. In the olden days, you'd see all kinds of crazy combinations of offensive linemen crossing behind the line of scrimmage to keep up with their assigned defenders -- that just wasn't very effective. 

Similarly, every NFL team runs some zone principles. Every NFL team has the outside zone in their playbook. Nearly every NFL team (except those fully committed to the Alex Gibbs school of blocking) also has Power O, Inside Zone, Counter, Iso Lead and a series of other plays in their playbook. 

And many of the teams that run primarily zone schemes still want big, physical offensive linemen. The Seattle Seahawks are a good example, but even the Tampa Bay Buccaneers over the past five years have run a lot of zone runs (with limited success). 

The key insight is that while a lot of those teams base a lot of their playbook on zone principles, they do not run the Alex Gibbs outside zone scheme. They don't fully commit to it. And the Bucs aren't likely to, either. 

Conclusion

We can't expect the Buccaneers to be successful along the offensive line by starting scrubs, just because they are likely (but not certain) to primarily use a zone-based offensive scheme. They still need quality linemen. They still need to block people. And they still (probably) can't start Oniel Cousins or Patrick Omameh at right guard and be successful. 

The Buccaneers are likely to be very innovative and versatile in their offensive line schemes, and they will likely do a lot with players who can be effective blocking in space, down the field. That's based on what Jeff Tedford and George Warhop have done in the past. Finding offensive linemen who can do that is not easy. Which is why a center who could do those things, was (depending on the measure you use) the highest-paid free agent offensive lineman this offseason. 

So, yes, the offensive line is a concern. And even if they ran the Alex Gibbs outside zone scheme exclusively, it probably still would be a concern, because even that scheme requires talent -- it just doesn't require overpowering linemen.