What Goes On Up Front?: Rules Involving Offensive Linemen

Linemen are the foot soldiers of football. The job of offensive linemen is to protect the most hunted player on the field – the quarterback – and to open running lanes for the backs. Football is primarily a running game and no team can be effective on the ground if the offensive linemen cannot win the war at the line of scrimmage.

This month’s column will examine the rules affecting what offensive linemen can and cannot do. Unless otherwise noted, the material applies to both NFHS and NCAA rules.

False start. The false start is the most often called foul in football. After the ball is marked ready and before the snap, it is a false start by any team A player if a charge is feigned or there is any shift or movement that simulates action at the snap or any team A lineman, other than an end, moves his hand or hands after having placed a hand or hands on or near the ground. The latter point refers to a "restricted" lineman and there is a subtle rules difference that would most likely be a factor in a scrimmage-kick formation. In NFHS, only the interior linemen are restricted; in NCAA, the ends are also restricted if they are numbered 50-79 (NFHS 7-1-7c; NCAA 7-1-3a4).

Play 1: Linebacker B5 fakes a blitz without entering the neutral zone. That causes interior lineman A9 to prematurely lift up from his three-point stance. Ruling 1: That is a false start by A9, a five-yard dead-ball foul.

Other examples of prohibited movement include: a lineman moving his foot, shoulder, arm, body or head in a quick, jerky movement; the snapper shifting or moving the ball or moving his thumb or fingers, flexing elbows, jerking his head or dipping his shoulders or buttocks; the quarterback chucking hands at the snapper, flexing elbows under the snapper or dropping shoulders quickly just before the snap; any player starting in motion before the snap and simulating receiving the ball by chucking his hands toward the snapper or the quarterback; or making any other quick, jerky movement.

Encroachment. For the offense any player, other than the snapper, who lines up in the neutral zone following the ready and after the snapper has touched (NCAA: or simulated touching) the ball, is guilty of encroachment. That is a five-yard, dead-ball foul. Both codes allow the snapper to be in the neutral zone. NCAA prohibits any part of the snapper’s body to be beyond the neutral zone, while NFHS permits the snappers hands to be beyond the foremost point of the ball if they are touching the ball (NFHS 7-1-7c; NCAA 7-1-3a-4).

Play 2: Tackle A10 breaks from the huddle, moves to the line and positions himself in the middle of the neutral zone. At the time A10 took his position, the snapper (a) had, or (b) had not placed his hands on the ball. Ruling 2: In (a), the whistle is blown immediately, A10 has encroached. In (b), encroachment does not occur until the snapper touches the ball. If A10 gets back to his side of the neutral zone before the snapper touches the ball, there is no foul.

Chop block. Star defensive linemen are frequently double-teamed. When two players block the same opponent, officials must ensure a chop block has not taken place. In NFHS, a chop block is a delayed block at or below the knees of an opponent (other than the runner) who is in contact with a blocker’s teammate in the free-blocking zone. Such contact outside the zone is an illegal block below the waist (2-3-7, 2-3-9).

Under NCAA rules, a chop block is an obviously delayed block anywhere on the field at or below the thigh of an opponent (other than the runner) who is (a) in contact with; (b) in the act of disengaging from; or (c) has just disengaged from but is still confronting a blocker’s teammate. A chop block is delayed if it occurs more than one second after a teammate contacts the opponent. Also, a high/low combination block by two nonadjacent linemen with or without a delay between contacts is a chop block. When in question, an illegal delayed block is at or below the thigh of an opponent and, as such, is a chop block (2-3-3, 9-1-2p).

Play 3: Second and 10 from team A’s 33 yardline. While right guard A8 is blocking defensive tackle B6 above the waist at team A’s 35 yardline, left guard A10 pulls and joins A8 in a double-team. A10 blocks B6 at the knees. Ruling 3: Under both codes, that is a chop block. If accepted, team A will be penalized 15 yards from the basic spot.

Play 4: First and 10 from team A’s 20 yardline. A8 blocks defensive tackle B6. The impact knocks B6 backwards. A8 then turns to his left and blocks B1. While B6 is no longer contacting A8, he is blocked below the knees by A4. A4’s block takes place after the ball has left the free-blocking zone. Ruling 4: Under NFHS rules, A4 is guilty of blocking below the waist. If accepted team A will be penalized 15 yards under the all-but-one principle. Under NCAA rules, that’s a legal block. B6 was disengaged from A8 and A8 was no longer confronting him.

Clipping. The clipping rule was written so that a player should not be hit from behind by an opponent he cannot see. Clipping is a 15-yard penalty. Blocks from behind and below the waist are clipping. A block from behind above the waist is an illegal block in the back, a 10-yard penalty. As with blocking below the waist, the legality of the block and whether it constitutes clipping is usually dependent upon the initial contact. Protection is not provided a player who turns his back to an oncoming blocker when the blocker has committed himself in intent and direction of movement (NFHS 2-5; NCAA 2-4).

Free-blocking and legal-clipping zones. In NFHS, the free-blocking zone is a rectangular area extending laterally four yards on either side of the snap and three yards behind each scrimmage line. NCAA calls it the legal-clipping zone and the dimensions are slightly different (10 by six yards). Neither zone can be expanded. The two zones serve the same purpose: to allow utilization of all aspects of football with minimal compromise of safety. From now on, I’ll refer to those simply as the "zone." In NFHS, blocking below the waist, blocking in the back and clipping are permitted within the zone provided certain conditions are met. In NCAA, with more liberal blocking rules, the zone only pertains to legal clipping and blocking in the back (hence the different name).

In NFHS, an offensive lineman who was in the zone at the snap may clip in the zone a defensive player who was also on the line and in the zone at the snap. Additionally, offensive and defensive linemen can block each other below the waist in the zone provided the opponent was on the line and in the zone at the snap, but only offensive linemen may block in the back in the zone. Those rights cease after the ball has left the zone (2-17).

In NCAA, offensive linemen in the zone at the snap may clip in the zone provided they haven’t left the zone and returned. The zone exists until the ball leaves the zone (9-1-2d).

Helping the runner. Although you don’t see linemen attempt to help the runner very often and it’s called even less frequently, it is a live-ball foul with a five-yard penalty if a linemen tries to give the runner an assist by pushing, pulling or lifting him to increase his forward progress (NFHS 9-1-1; NCAA 9-3-2b).

Holding. The offensive line is also essential to the passing game. Linemen must shield the quarterback for enough time, usually two to three seconds, to find an open receiver. Linemen sometimes overprotect by illegally restraining the defender.

There are two basic legal positions – either with closed or cupped hands and the forearms within 45 degrees of the body, or open hands with palms facing the opponent and arms extended from the body as far as the blocker wishes. The cupped hand technique requires that the palms not face the opponent and the elbows or forearms may not be thrown into the opponent faster than the blocker’s shoulders at contact. The open-hand block requires the blocker’s hands be inside his own frame and also within the opponent’s frame on contact. The blocker is allowed to contact the back of the opponent if the opponent spins during the block or after the blocker is committed to his charge. Violations result in a holding penalty, 10 yards from the basic spot (NFHS 2-3-2, 9-2-1a Pen; NCAA 9-3-3a).

Ineligible receiver downfield. Interior linemen are ineligible receivers. Team A players who are on the ends of their scrimmage line and are numbered 1-49 or 80-99 are eligible receivers. Interior lineman are restricted from going downfield on a play on which a legal forward pass crosses the neutral zone. The tackle eligible play is illegal.

Ineligible team A linemen are not illegally downfield if they immediately contact a team B lineman and drive him back provided the contact does not continue beyond the two-yard expanded neutral zone (NFHS) or three yards (NCAA) (NFHS 7-5-12; NCAA 7-3-10 Ex 2).

Play 5: Third and five on team A’s 30 yardline. A1 throws a forward pass well downfield. While the pass is in flight, guard A6 is blocking B3 at team A’s: (a) 30 yardline, (b) 32 yardline, (c) 33 yardline, or (d) 35 yardline. A6 began contacting B3 right after the snap and on team A’s 30 yardline and sustained the block. Ruling 5: Under NFHS rules, legal plays in (a) and (b); offensive pass interference (and ineligible illegally downfield) in (c) and (d). Under NCAA rules, legal plays in (a), (b) and (c); same as NFHS in (d).

Written by George Demetriou. A football official since 1968, he works for MCI and lives in Colorado Springs, Colo.