When an offensive line on the NFL level utilizes zone blocking principles, they usually want more athletic linemen. Think of the great Denver Bronco running attacks from around 15 years ago. All five of those guys were smaller and quicker that their contemporaries at the time. The Bears, under Mike Tice, want bigger, bruising type linemen, which is why I wasn't sure if they used any of the zone scheme stuff. A recent article in X&O Labs that quoted Bears tight end coach Mike DeBord leads me to the conclusion that they do use some zone blocking.
I'm writing this article for a couple reasons, one, there's the obvious Bears connection, but two, I'm contemplating doing some zone stuff this football season with the team I coach. I can pass along some info to you all, and learn a bit more myself.
In zone blocking all the linemen and inline tight ends will step play side in unison and block what ever crosses their face. Sometimes they end up double teaming, sometimes their track takes them to a linebacker, and sometimes their path leads them to a stunting lineman. This uniform action by the o-line gets the defense flowing and as long as the o-line stays with their blocks and on their track it creates lanes for the ball carrier to run through. The running back has an aim-point, but he's not really running to a hole. Where he runs is predicated on the defensive front. The three basic runs in this scheme is inside, outside, and stretch. Often times on TV the analyst will mention that an offense is running a stretch play, but you'll rarely hear him reference an inside or an outside zone run.
On the inside zone run, the back is running towards the 1st defensive lineman play side (in a 4-3, the DT), then making one cut off his o-lines block. The outside zone run usually has the back running towards the 2nd defensive linemen (in a 4-3, the DE), then making one cut and going. The stretch play is designed to run towards the last man on the line of scrimmage, sometimes the DE, but sometimes a walked up outside linebacker. The back is looking to stretch the play out, make one cut and go. As you've probably recognized by now, the back is to make one cut. No dancing in the hole, no stutter step, no cut out then cut back. One cut. Then get what you can. I think Matt Forte is a great candidate for the zone scheme. Some of his biggest runs have come on a one cut and run to daylight play.
Another key to zone blocking is leaving the end man away from the play alone. If that backside DE or LB is chasing down your back, it's time to find a new back.
I've used some zone concepts on the backside in years past, but this year we're considering it as our base scheme. Many zone teams teach to cut the backside pursuit. I don't necessarily agree with this technique. I have no problem with cutting, as long as it's done from the front and above the knees, but simply cutting the backside seems lazy. The way we teach the back side is no different than the front side. Get on your track and block whatever crosses your path. We emphasize shutting down the inside gap and we make sure our backside TE or tackle knows not to chase the end man if he stays outside and away from the play.
There's obviously a lot more to the scheme, whether the o-line are covered or uncovered will give them their rules on the play, some zone teams pull linemen on occasion. Some rules change depending if there is a fullback leading the play. If you're interested in the nuts and bolts of zone blocking I'd recommend the above linked X&O report. And believe it or not Wiki has some good stuff too.