How do you identify eligible/ineligible recievers?
 

Please respond

Is he an end?
Is he a back?
Is he wearing an eligible number?

Three simple rules
 

1) Jersey numbers 50 thru 79 are always ineligible regardless of their position on the field.
2) The two players on the end of the line of scrimmage are eligible unless they are wearing 50-79.
3) Any and all players not on the line of scrimmage are eligible unless they are wearing 50-79.

To be eligible you must meet two criteria:

1) Have a number between 1 and 49 or 80 and 99 (eligible by number)
2) Be in an eligible position -- on and end or in the backfield (eligible by position)

You have to be eligible by number and position; otherwise, you are ineligible.

Are you asking about MECHANICS of which crew member(s) identify eligibles and ineligibles? Or are you asking about the rules of who is eligible or not eligible? The rule portion of your question has been answered above.

im pretty much asking both

Determining eligibles is primarily the responsibility of the wings - the Head Linesman and the Line Judge. It's pretty simple. First of all, numbers 50 through 79 are ineligible no matter where they are (we won't get into 4th down numbering exceptions now). By position, backs and ends are eligible so....

You have to look at the player on the end of the line on your side, he could be split wide on in tight, but whoever in on the end is eligible (assuming proper number). Make note of him.

Second, look to see who is on the line inside him. If its' an illegible number (it's usually a tackle numbered in the 70's) then no problem. You don't have to track or remember him. If it's an eligible number and he's covered (inside the end and on the line) make note of his number and see where he goes on a pass play. If he goes downfield on a pass that crossed the line, you have a foul. This usually happens when a wide out sets up on the wrong side of the field or a player, who should be in the backfield, mistakenly lines up or shifts to the line.

You also need to note the backs on your side (see the keys in the official's manual on who you have to track.)

That's pretty much it. As far as eligible/ineligible goes, the only worry you have is tracking a player with an eligible number who is lined up in an ineligible position.

Example, 88 is split wide on the line. 86 is on the line inside him. You are probably the only one on the crew who will know 86 is ineligible. The BJ can't always tell if 88 is on the line or not. Once the ball is snapped and 86 goes down field, there is no way for anyone to tell if he's eligible so you better have noted it and watched him.

It's also good to remember who your eligible were in case there is a question. If a coach or even another official suggest that number 88 or number 32 wasn't eligible, you can tell them that 88 was on the end and 32 was legally in the backfield. If they ask about 88 and you have a blank look on your face, you have problems.

Try to get into the habit of looking at shirt numbers as they break the offensive huddle so you can pick out your eligibles as early as possible. If you see only one eligible number coming your way, then you are expecting the guy to be on the line.
If you see two (or more) coming your way, then you expect one on the line and one off the line. If they mess up and both are on the line, be sure to know what the "covered" guy does if there is a pass across the NZ. He may be ineligible downfield. Only the wing guys can catch this - the Umpire will only be checking the 50-79 numbered guys being too far downfield.

Note-In this scenario, young officials (or not so young) must be cautious to wait for the pass before dropping the flag. I've seen officials throw the flag as soon as the ineligible goes down field. Under Murphy's law, if you jump the gun you can guarantee that no pass will be thrown. Then you get to explain to the Referee the situation and the flag is then waved off.

Exceptions
 

However, you will also get into numbering exceptions--when teams do not have to have 5 players 50-79 in the game. This occurs in scrimmage kick formations and can cause trouble if people (and especially the U in this situation) are not paying attention.

This is also how the California coach was able to run his A-11 formation where he has all eligible numbers on the field and his formation will determine who is eligible and who is not for every down.

So just to be sure we are on the same page.......The two players on the ends of the line ARE eligible provided they are wearing an eligible number, Everyone in the backfield IS eligible provided they are wearing a eligible number, and everyone else is INELIGIBLE. (Assuming that its not forth down)

Am I Correct?

If I am, If one of the two ends or both of the two ends is off the line of scrimmage are they still eligible?

First down, fourth down, it doesn't matter. A player's eligibility is determined my number and position. The number of the down has no relevance.

If a player is not on the line of scrimmage he can not be an end.

One of the most common points of confusion relating to understanding football rules is getting tied up in the "language" of football.

There are hundreds of terms or descriptions that capably and effectively describe very specific situations that simply cannot, or at the least should not, be used to describe other situations.

A commonly misused term is "end". Every line, including those in football has two ends, one on one side, one on the other. There are two inseparable requirements for any player, who is on the line of scrimmage to be eligible to catch a forward pass; he has to be standing on the outside edge, the "end" of either side of the line and wear a number between 1-49 or 80-99.

A "Back", basically, is anyone not on the line and behind it (Actual definition is NF: 2.32.3). If that back also wants to be eligible to catch a forward pass, he too, has to be wearing a number between 1-49 or 80-99.

If a player is wearing an eligible number, and is anywhere on the LOS, but either end, he's not eligible by position. If #88 lines up on one end, and #22 shifts to a position wider towards the sideline, and makes the mistake of moving up to the LOS, he's still an eligible receiver but he's taken eligibility away from #88, who is no longer on the end of the line.

Now, as often happens, when #22 steps up to the line, #88 takes a full step back, establishing himself as a "back", and he retains his pass catching eligibility.

Everyone harps on reading Rule 2, becuase it's so important to know and understand what the "official" definitions actually are. Thery are the only definitions that count and may be ever so slightly different than definitions all sorts of people use to try and describe things.

There is simply no getting around knowing and understanding Rule 2.