Got my first semi pro game tonight. Anyone care give me a quick rundown of how blocking below the waist and clipping is called in the NFL.

12-2-12 Blocking below the waist is prohibited by any player after any COP. All players are prohibited from blocking below the waist during a down in which there is a KO, safety kick, punt, FG attempt, or try. Exception - players on the receiving team lined up inside the normal TE possession can BBW immediately at the snap on punts, FG's or trys.

12-2-9 There shall be no clipping from behind below the waist against a non runner. This does not apply to offensive blocking in close line play where it is legal to clip above the knees, but it is illegal to clip at or below the knees.

Clipping exceptions;
1. allowed in close line play, tackle to tackle, 3 feet on both sides of NZ
2. legal on LOS above knees only
3. may not clip a defender more than one position away
4. any offensive player more than 2 yards outside the tackle may not come in box and clip or BBW (illegal crack back). If the passer scrambles and significantly changes direction of play, the block is legal as long as it is not UNR.

Hope this helps. Good luck, and have fun!!!

thanks for the info and the quick reply

NFL Crackback rule:

If an offensive player is lined up more than two yards outside the tackle ("flexed player"), or if a back DURING THE PLAY moves more than two yards outse where the tackle lined up, he may not block below the waist if the blocker is moving towards the position of the ball at the snap. The block is illegal only of the block occurs within five yards on either side of the line of scrimmage.

However, if there is a scramble that clearly changes the flow of the play, you may legally crackback!