NF Spot Question
 

From A's 10yd line, A1 passes to A2 who runs to the B10. While being tackled,A2 grabs and holds B10's fasemask. What is the penalty enforcement?

The spot of enforcement is the end of the run. This is a 15 yard personal foul. Mark it off 1/2 the distance - A's ball, first and goal from the B5.

NF: You don't say where the run ended, but I'd go with a 5-yard markoff against team-A from the EOR.

Walt - The foul is on A, not B.

Theisey - All fouls are enforced from the spot of the foul when the spot of the foul is behind the basic spot - 10-6 (in this case, the basic spot is the end of the run).

So we penalize 15 yards from the spot of the foul, 1st and 10, A. (I interpret "grab and hold" as fitting the parameters of "grasping" - 9-4-3-h.)

(I'll admit I'm splitting hairs if the foul being committed "while he's being tackled" is the exact same spot as the end of the run, but it's still techincally enforced from the spot of the foul. I've seen tackles that take 10 yards to complete. For instance, if he started being tackled at the B18, grasped the facemask at the B15, and then was finally downed at the B10, we wouldn't give him those 5 yards he got after committing a foul to be penalized from.)

It was my assumption that EOR was the same spot as "being tackled".
Otherwise, I would agree the spot of this team-A foul could be different than the EOR.
I will not argue the 5 vs 15 yards as this would have to be a have to see. However, the original post did not mention any twisting in the statement of the play, hence I will go with the 5 yard version of the foul.

9-4-3 Doesn't say anything about twisting, but I agree, HTBT for most face mask fouls.

The rule itself does not address the penalty portion of a face mask foul. All it is saying is that is is a foul.
By now, we all better know there are two forms of this foul, the 5 yard and the 15 yard variety. This was a year 2000 rule change.

The penalty section for 9-4 does point out the grasping vs. grasping and twisting differences.

spot foul
 

this is enforce from the end of the run, I would have to disagree with hawkeye that it is from the spot since this fouls would not be 'behind' the basic spot because it was on B. (unless of course the runner broke free after the foul and ran backwards before being tackled) then it would be form the spot (behind the basic spot (For B))

Yeah, I realized that when I read Theisey's response. My bad. :(

oops didnt realize the penalty was on A either.

Semantically speaking, unless the foul is beyond the end of the run, the enforcement is from the spot of the foul. If the spot of the foul is the end of the run, so be it.

I had never seen a runner actually grab a face mask but this year, I've seen it twice.

Actually, all fouls on the offense are enforced from the basic spot, except when the spot of the foul is behind the basic spot. The basic spot isn't necessarily the end of the run. I know that's being picky!:)