Football's Zone Blocking Rules

Historically, offensive line play in football involved one-on-one confrontations, with burly offensive linemen overpowering their defensive counterparts to open running lanes. Yet teams without big, powerful offensive lines devised the zone blocking scheme to benefit smaller, more athletic linemen who can use speed and leverage to their advantage. When zone blocking, offensive linemen blocks gaps, or areas of the field between blockers, and not necessarily one specific defender. While individual schemes may vary, zone blocking relies on a few general rules.

Covered

In a zone blocking scheme, the offensive lineman's responsibilities change depending on whether he's covered or whether a defender is lined up directly in front of him. A covered lineman still must block his assigned defender, just like in a traditional blocking scheme. However, because it's a zone, the offensive lineman blocks the gap on the play side. In other words, if the play calls for the run to go right, the lineman will step into the gap and block the right side of the defender, creating a seal.

Uncovered

If the offensive lineman is uncovered, meaning that no defender is in front of him, his job in a zone scheme is to slide into the play-side gap, secure the area, offer double-team assistance to his play-side teammate and then quickly move into the second level to engage any free linebackers or defensive backs. Uncovered offensive linemen, and the decisions they make, are critical to zone blocking success.

Outside

Zone blocking may be either inside or outside. In outside zone blocking, the offensive linemen try to gain leverage on the outside of the defender, forging a seal for the runner along the sideline. If defenders recognize the outside movement and overplay in that direction, the offensive linemen use the defender's momentum against him, driving him all the way to the sideline and opening a cutback lane for the runner.

Inside

Inside zone blocking also attempts to use the defender's momentum to create a cutback lane, except the designed hole falls between the tackle and guard and not outside the tackle. The same basic rules govern inside zone blocking, with the linemen double-teaming according to whether or not they're covered. The main difference in inside zone blocking is that the running back reads the outside hip of the play-side guard, ideally cutting the ball between the guard and tackle.

Warning

Zone blocking features a lot of double-team blocks, with an uncovered lineman stepping in to help his play-side teammate. When moving across to block the already engaged defender, the double-teaming lineman must block the defender above the waist. Cutting an engaged defender below the waist or knee can be extremely dangerous for the defender, creating an increased risk of injury. Because of the seriousness of the infraction, officials will call a chop block and penalize the offensive team 15 yards.