Since we've been discussing IS and IP, consider this play:
<b>PLAY:</b> A, 2-14 from B's 30. The ball is snapped. B13 then realizes that his team only has 10 men participating and comes running onto the field at the 50. A35 carries the ball to B's 27 where he is tackled. B13 is still way behind the play when the ball becomes dead. <b>RULING:</b> ???

Since the entering substitute didn't influence the play you have a live-ball illegal substitution foul (non-player version of the IS rule 3.7.1). This foul is enforced similar to USC which is a "non-player" foul marked off from the succeeding spot.

After the penalty is administered it's 3rd and 6 from the 22.

See the "Penalty" section under rule 3 sec 7 (page 36) of last year's rules book.

Maybe. What if B13 was the 11th player from the previous play who for some reason stepped off the field during the dead ball? Since there has been no subsitution, he is still a player.

Once he withdraws he can't come back unless there is an accepted penalty (the punter rule), a TO or a quarter change. Even if B only has 10 players, he's a subsitute.

In this year's points of emphasis, they harp on this.

Not exactly. I read this in a posted article somewhere...possibly in Referee. If a player goes off the field and was the 11th player when he went off he's still a player by definition, not a substitute. So he's allowed back in. Many officials think this is illegal but it's not. Actually, it's illegal if the player does it to gain an advantage such as pretended substitution therefore making the other team think he's left the game. So really it's an official's judgement. But agan he's still a player so he can technically re-enter.

I didn't address Jim S's comment. Because he's still a player by definition I'm guessing that if he's on the opponent's side of the LOS and the RFP has been given you may have an immediate dead-ball encroachment foul.

I guess????

It would have to be after the center puts his hand(s) on the ball unless he was in the neutral zone giving signals or touches the ball.

So the question remains if the 11th player steps on the field after the snap do we have a foul?

REPLY: I think you do. By definition (NF 2-30-15), if he enters the field to fill a player vacancy (even his own!) he's an entering substitute. In which case, he's violated NF 3-7-1.

Well don't we also need to consider 2-30-1?

Good Point LJ...

I would've sworn that this is a foul, but a player isn't replaced until his replacement becomes a player... Since there was no replacement, the 11th guy is still a player...

The key part of 3-7 says, "... and no player shall withdraw and re-enter as a substitute unless ..."

The book doesn't define withdraw, but this player in question is not re-entering as a substitute..

Therefore, in the original question, I would say that the player is guilty of encroachment as soon as the center touches the ball and the player is on the wrong side of the neutral zone... If the player was never on the wrong side of the neutral zone, everything seems to be okay... I can't find a rule to prevent him from stepping onto the field after the snap, either...

Feel free to punch holes in the logic...

Haven't looked in the rulebook so this may be incorrect.

You can have IP if the player does not come within 15 yards of the ball before the snap. Most likely a player running on the field has not come within the 15 yards.

PiggSkinn. Wouldn't call encroachment on this one. A player can get back to his side of the LOS even after the Ref blows the RFP. besides he may not be encroaching the NZ when the snapper placs his hands on the ball, he may be behind it.

Snake~Eyes - The 15 yard rule applies to A only... (7-2-1) Good thought, though...

Jim - I was going to get into the technicalities of encroachment after the last question was resolved, but since you brought it up...

Encroachment refers to being illegally <i><b>in</b></i> the neutral zone, but makes no reference to being beyond it... (Except for free kicks, where encroachment is defined as being beyond the free kick line...) I have found nothing that states it is a foul to be on the opposite side of the neutral zone at the snap...

So, by the strictest of interpretations, the 11th B player is not encroaching when he is on A's side of the ball... At the same time, he is not covered by the illegal substitution provisions (3-7) because he is not a substitute... So as long as he does not touch a player, touch the ball, give defensive signals, or cross the neutral zone to get back to his own side of the ball, he has committed no foul...

Obviously, this isn't correct... Please, someone find a rule that covers this...

(The only possibility I can come up with is by using 7-1-6 and adjusting the definition of "breaks the plane of the neutral zone" to include being beyond it...)

I thought that'd be the case.

OK PiggSkin, I'll relent. There is a foul there. It's not IS because he is still a player unless you determine that he left the field to gain an advantage. It's not IP same reason. It is (drrrrrrrrrrrrrrrr(drum roll)) a numbering violation. 5 yard foul at the snap. You see the numbering violation section is the only place in the rulebook where it defines where B can be. It says B players must be on their side of the LOS. When discussing position it is assumed but not stated that positions are on the field of play.
We're not going to let him get away with coming on after the play starts.
This BTW is the same foul if a B player lined up in the A backfield and A snapped the ball. Numbering violation. 7.2.5 Have won a lot of bets with this rule.

We're really parsing words here, but...
 

That's close, but if you had bet me, I still wouldn't be paying... :D

7.2.5(a) says:
At the snap at least seven A players, five of whom must be numbered 50 to 79, shall be on their line of scrimmage. B players <B><i>may</i></b> be anywhere on or behind their line...

It doesn't say "shall", "must", or anything like that... It just states that it is permissible... (As opposed to the positional requirements of A...) At best, in only implies what we're looking for... The book has got to be more specific than that...

Plus, there's no way I'm gonna go out and announce the foul as Numbering violation... It just doesn't make sense...

Hold on Jim S. I wish you had a bet with me. 7.2.5 has nothing to do with the play in question and is not the only place in the rule book where it defines where B can be. For starters, checkRule 2.8, 2.24.3, 7.1.6

Nah Bob. None of those require a B player to be on his side of the LOS to Start the play.
2.8 defines encroachment (a place where no player can go)
2.24.3 only defines what is a defensive lineman, doesn't require anyone to be one.
7.16 again deals with encroachment. Again does not require that a B player be lined up on his side of the LOS, only that he not encroach the NZ.

A previous post stated that 7.2.5(a), Numbering requirements, was the only reference in the rules about where B could be. I was pointing out that there were other references and I still maintain they are all pertinent, although none of them relate to the original play in question. And I left out 3.7.6 which says an entering substitute shall be on his side of the neutral zone when the ball is snapped or free kicked. That's pretty clear. Now if you are going to say the player was not an entering substitute but one who was already in the game, then he also may not encroach. Take your pick of the rules making encroachment a foul.