NF Rule 2-17 details the FBZ. In order for a B player to be legally blocked below the waist or clipped, the A and B players must both have been on the line of scrimmage AND in the FBZ at the snap. On the line of scrimmage for B players is within 1 yard of the NZ (2-25-3). In order to be legally blocked in the back the B player must only have been in the FBZ at the snap, but there is no requirement to be on the line of scrimmage in this case. The A player must be on the line of scrimmage in all cases involving clipping, BIB and IBW.

There was a sit. last year with these types of questions. It involved the "second block" as described in the case book. An initial hit below the waist is legal, but a second hit is not. Case play 9.3.2 Sit F. The one team I had also delayed the initial hit and then went for the legs, which the one coach did not like, as it was a safety concern for his players. Sometimes they were committing it while the ball was in the ENZ, and most of the time the ball was out, so that was an easy flag. It was the times where the ball stayed in that made things tricky, for they were "going for the knees" for the takedown. How does anyone else feel about that?

The most difficult illegal block in the zone to recognize, process and react to may be the linebacker, or defensive lineman going thru the NZ and taking out interference with a low block.

NF: 2.17.2.a advises "All players involved in the blocking (below the waist) are on the line of scrimmage and in the zone at the snap."

Rule book writing is tough.

What is being stated in the Rule Book simply is they do not want a player to have the momentum of charging into the zone and blocking below the waist or clipping because of the danger.

Before the rule was re-written it allowed a player to come into the zone and perform those blocks before the zone disintegrated. If I remember the commentary on the change correctly it emphasized the danger of injury especially to the knee.

If Fed wanted to outlaw all BBW, they'd've written it that way. There are some governing bodies stricter than Fed re BBW. What's that lawyer's saying in Latin that translates something like, "The inclusion of something works to the exclusion of other stuff."? The mere delaying of a hit at the level of the knees (absent the other factors of chop block, etc.) is not per se illegal in Fed, although it would be in WPFL. Sometimes the only way to keep a fast opposing DL from beating a trap block is to lunge and cut or clip. Does that endanger the cruciate ligaments? Of course it does, as has been recognized for a century, but if such concern couldn't be compromised they'd outlaw clipping even against the runner.

Robert

From the 1995 Rules Book "A block from the rear is used in quick "trap" plays and "misdirection" plays. A defensive lineman is allowed to penetrate and is then contacted from behind by a pulling offensive blocker. The purpose of the free-blocking zone is to allow utilization of all aspects of contact with minimal compromise to safety."