The following is an answer to a question buried deep in another thread. I wanted to entertain questions from a wider audience:

 

1. A chop block is essentially a double-team block in which at least one of the blocks is below the knees. It is always illegal, even if in the free blocking zone and even if the "double team" is not intentional. It is a severe player safety infraction which causes knee injuries.

 

2. Blocking below the waist and clipping are legal blocks if they occur in the free blocking zone between two players who are both on the line of scrimmage at the snap. If a defensive player is in the zone and within one yard of the LOS at the snap, he is considered on the line (ie, a blitzing linebacker). Blocking in the back is legal anywhere within the zone so long as the blocker is an offensive lineman, against a player in the zone at the snap, and the ball has not left the zone.

 

3. The free blocking zone is a rectangular area extending laterally 4 yards either side of the spot of the snap and 3 yards behind each line of scrimmage. A tight end is rarely in the zone, a running back is never in the zone, a linebacker is usually in the zone. A shotgun formation does allow for an immediate legal block below the waist or in the back which occurs simultaneous with the snap. All blocks must be above the waist at all times during a scrimmage kick (punt or field goal) or free kick.

 

4. Don't confuse the terms cut block, which is coach-speak for (presumably) a legal block below the waist, and chop block which is always a foul.

 

offside

3. The free blocking zone is a rectangular area extending laterally 4 yards either side of the spot of the snap and 3 yards behind each line of scrimmage. A tight end is rarely in the zone, a running back is never in the zone, a linebacker is usually in the zone. A shotgun formation does allow for an immediate legal block below the waist or in the back which occurs simultaneous with the snap. All blocks must be above the waist at all times during a scrimmage kick (punt or field goal) or free kick.

That explains all those penalties I received.

Can a defender ever "block below the waist"? For example: on PAT a defender lines up outside the "TE" and crashes down into the outside leg/knee of the said TE while the TE is blocking a defender lined up over him. It seems dangerous to allow the defender a free shot at the leg/knee of the TE.

 

Thanks.

Can a defender ever "block below the waist"? For example: on PAT a defender lines up outside the "TE" and crashes down into the outside leg/knee of the said TE while the TE is blocking a defender lined up over him. It seems dangerous to allow the defender a free shot at the leg/knee of the TE.

 

Thanks.

 

I think you just described a chop block on the defense! This foul is not necessarily limited to the offense.

 

It is possible for a Defensive Lineman (or linebacker who's within 1 yard of the LOS) to legally block below the waist within the free blocking zone. A defender on the LOS on the outside shoulder of the TE is NOT going to be in the zone. Seems strange, but defensive linemen do "block" in a gap control or goal line defense.

 

It is more common to see a flag thrown against a defensive back who takes out the legs of a lead blocker on a sweep--illegal block below the waist on the defense.

 

offside