Does your R bag the spot of the pass on a play close to the L.O.S.? We've talked about this mechanic a lot and our
R bags the spot- the U should be at the LOS, but we want the double-check.

What do other crews do?

I bag the spot
 

we had this exact situation come up in our first varsity game of the year. I bag the spot as the R then I can look after the play is over...in the game I mentioned my U threw a flag to mark the spot, I subsequently waived it off....I hate to do it that way...but in my opinion all close looks should be bagged not flagged, this keeps you from having to waive one off....

AR mechanics
 

The U if in position to see, will flag.

As R, if the pass is close, I move to the spot of where the pass was thrown and if close, I drop my flag AT THE SPOT and continue to officiate. Upon dead ball. I move to the flag and check to determine if the flag is beyond the LOS. If it is not, I will wave off the flag.

Illegal pass- flag or bag
 

This mechanic comes down to whether you would rather bag the spot and throw a late flag if needed- or if you would rather drop the flag and pick it up if needed.

We would rather drop a rather have the R drop the bag and throw a late flag if needed. Since the flag will be past the stake on an illegal pass the late flag is pretty obvious and easy to explain.

In our association, the Umpire will make this call 4/5 times. He's up on the line anyway--so he makes calls such as if the QB went past the line, if a screen pass went across the line, etc. etc.

But on that instance when it's close, and he has to continue officiating, and the Referee has to continue officiating rather than looking... most crews I've talked to prefer the bean bag/late flag procedure. I personally think it's MUCH easier to explain to the offensive coach that you were making sure you got it right than to explain to the defensive coach that we're picking up a flag. They see the flag, they want that penalty...

Had this happen last year, umpire threw flag. I (referee) dropped bean bag. Play was away from chains, in side zone, so umpire had to "turn around" to check if it was past LOS. After looking at the bean bag, it was clear the passer was behind LOS. My spot (bean bag) was better. Mechanics book says this is the R's call with assistance from the U/HL. I stress (in Pre-game), the R will make this call, with assistance (only if it is towards chain side and obvious) from U (and then U may throw this flag).

If your are fortunate to work the game with 6 or 7 officials, the LJ camps out on the line of scrimmage and it's his responsibility to see and flag this as necessary.

Otherwise, let the R bag and flag later in the play.

I'm in the flag first & wave it off later camp for one major reason: Chain crews (and specifically the box guy) are instructed to stay put if they see a flag on the field. (And hopefully they won't miss a flag thrown right around the LOS.) They don't have the same strong prohibition on a bean bag. I think you're more likely, with a less-than-perfect crew, to be unable to correctly determine this if you drop the bag than if you throw the flag.

My chain crews are instructed to stay put until I tell them to move.

The people on the actual chains are told to stay put until the HL signals, but the box man is not instructed as such. The problem I see with having the box man move on a signal is if I, as the head linesman, signal the box man to move, someone with the chains might also move.

I was speaking as HL, not as R. I make sure to differentiate. I say boxman just for the box, chains for the crew, this is explained in pregame.

I explain to the chain crew I have two signals. One is where I will raise up the down, this is his key to move. Not until then. I've had good success with this.

The other is a sweeping of the hand, which means move the chains.