expanded neutral zone
 

When is the expanded neutral zone used and what is it used for?

The neutral zone may be expanded to allow for normal line play. For example, you wouldn't have an ineligible down field foul if the offensive lineman is blocking a defender within 2 yards of the line of scrimmage. It also applies to low scrimmage kicks that are touched by R when attempting to block the kick.

Rule 2-28 Neutral Zone

ART. 1 . . . The neutral zone is the space between the two free-kick lines during a free-kick down and between the two scrimmage lines during a scrimmage down. For a free-kick down, the neutral zone is 10 yards wide and for a scrimmage down it is as wide as the length of the football. It is established when the ball is marked ready for play.

ART. 2 . . . The neutral zone may be expanded following the snap up to a maximum of 2 yards behind the defensive line of scrimmage, in the field of play, during any scrimmage down.

Walt's got your answer. As you can see, Rule 2 is your friend! :)

A follow-up question you might have is "Why is there an expanded neutral zone?"

One reason the neutral zone is expanded is to allow the defense a chance to block a scrimmage kick (punt, or field goal) without worrying about touching the ball beyond the normal line of scrimmage.

But also note the neutral zone never expands into the end zone.

FG Attempt, ball snapped at the 1. B99 blocks the kick 1 yard deep in the end zone. He has touched the kicked beyond the LOS. Not really a big deal, because if the kick does not score it is a kick which has broken the plane of R's goal line, touchback!

BUT

3rd & Goal on the 1. Right Tackle A75 Blocks and pushes B99 1 yard into the end zone. (2 yard block) QB A1 rolls right and throws a forward pass into the end zone to A88. A75 is an inelligible downfield and may be guilty of OPI.

In the book it states the following.

NF 2-28-2 The neutral zone may be expanded following the snap up to a maximum of 2 yards behind the defensive line of scrimmage, in the field of play, during any scrimmage down.

If it only extends on the defensive side, how does it help them to legally block a scrimmage kick?

It allows a defensive player to not necessarily penetrate the line of scrimmage and still block a low srimmage kick and NOT have it count as a touched kick beyond the neutral zone.

Because if R touches the ball beyond here without an expanded neutral zone, the team in possession at the end of the down would have a new series (1st down).

Brandon, this is an example of how Rule 2 definitions can help in understanding the other parts of the rule book.

For example, Rule 6-2-6 (the rule number might be different as I only have the 2006 book with me right now) states:

"The touching of a low scrimmage kick by any player is ignored if the touching is in or behind the expanded neutral zone. The neutral zone shall not be expanded into the end zone."

Also, look at 5-1-3f:

"The team in possession at the end of the down, if R is the first to touch a scrimmage kick while it is beyond the expanded neutral zone, unless the penalty is accepted for a non-post-scrimmage kick foul which occurred before the kick ended."

The expanded neutral zone gives R the chance to block a low kick without risking giving up the football because they touched it.

The expanded neutral zone is used in another place, and that is in regard to an ineligible receiver down field. Can you find the specific rule? Hint, it is in Rule 7. :)

Yup I found it! its 7-5-12
This means that if an ineligible reciever is in or behind the expanded neutral zone and he makes immediate contact with B it is not a foul Correct?

Essentially. The purpose of the rule is the allow for normal line blocking without a lineman committing a foul for being downfield.

Good job on finding the rule, now keep reading. ;)

In addition to the Redding Guide that ajmc recommended, I've found the NFHS Rules by Topic to be useful in learning the rules. This book breaks the rules down by topics and includes case plays from the case book in the same section.

It also expands when the umpire stands over the ball during a time-out.:D

You should also note the defensive player is on his line of scrimmage when he is within one yard of the scrimmage line 2-25-3.