Sometimes, you hear the announcers say that an offense has made a tackle eligible as a receiver on a play. It’s usually a goal-line play. What i want to know is, is there a limit on how often a team can declare a tackle eligible to catch a pass? Or is it only allowable in certain situations (like inside the 5 yard line)?
If there is no explicit limit, what would stop a team from declaring a tackle eligible on every offensive play?
Nothing’s stopping them, per se. But if you have a tackle that you want to regularly put in as a ‘sixth lineman’ & have him eligible, why wouldn’t you just call him a tight end and be done with it? That’s all that’s really going on here; the team is just putting in a second (or third) tight end, except that the guy they want doing it is ordinarily a backup offensive lineman & doesn’t have a number in the correct range; so they’re required to alert the other team. “I know this guy’s actually an OT, but for this play, we’re using him as a TE instead.”
If you’re regularly running multiple tight-end formations, you should probably get a real tight end to fill that slot.
Or were you thinking that by declaring a ‘tackle eligible’, you’re allowed to have only four ineligible down linemen on the field? :smack: That’s not what’s happening … You still have five ineligible linemen on every play. This lets you legally put in a sixth lineman in a tight-end spot, even though his uniform number is outside the normal range for receivers. It’s to get a bigger blocker on the line for a goal-line push, not to get an extra person to throw to. Actually sending a pass that way is definitely a gimmick play–which is why it sometimes works when they try it, even after having to announce the option to the other team. On this play, we could throw a pass to 6’ 6", 475 pound, 6-minute 40-yard-dash-running Joe Fumblerooski–but who’d actually do that, right? 
The assumption by the defense is that Joe will be helping to plow a path into the end zone for the running back, and their response will be to stack the line, and probably sub some extra defensive linemen for linebackers or safeties. If Joe fakes missing a block, he might run free into the end zone & be wide open. Then, if he can just keep that little, tiny football from slipping between the hamhocks he calls ‘fingers’, he might get his first ever NFL touchdown!
That’s more clear. So it’s for running reasons. There are a couple of players who specialize in catching out of this formation (Mike Vrabel, for example), so it was not that clear to me that he’s the exception, not the rule.
Another fun variation we used in college was swapping the jersey of the offside tackle with an eligible number so we didn’t have to declare him eligible. We would come to the line with our chests low so that the numbers didn’t show as much. A receiver and a tightend lined up outside of him and then shifted the tightend to the opposite side of the line, making the tackle eligible and the tightend ineligible. The QB would run a naked boot to the eligible tackle side and the tackle would pretend to screw up and go to block the corner. No one covers the a lineman out to block a DB on what looks like a QB run and we won two games in 5 years with this as our two point play. Worked every time we ran it.
Really? There’s no rule against changine jersey numbers during a game?
(Is there such a rule in the NFL?)
What is the rationale for having a rule that some players are not eligible receivers? Is the rule a reaction to some long-ago strategies that were getting too many people hurt?
IIRC, a long time ago, these eligible linemen had to put on a special jersey of some sort over their regular jersey for the play.
If ANYONE becomes eligible for a forward pass, the pass becomes nearly indefensible. It’s damn near indefensible in the CFL, where more than one person can be in motion behind the line at a time, and can have a running start forward at the snap.
I’ll just ask, if you are an eligible receiver you are allowed to do a forward pass?
I was watching a movie where this happened.
Sure. Anyone can do a forward pass (just so long as a) no one else has done a forward pass that play and b) you’re behind the line of scrimmage.