What makes an NFL formation legal vs. illegal?
As a young NFL fan, I could not figure out how the chains measured for a first down. No matter how many times my grandfather tried to show me how the ball was either past the chain link or not, I just didn’t see it. It was a major victory for me when I finally recognized what had been in front of my eyes.
Over the years, I’ve discovered more aspects of the game that I didn’t know before. When Leon Washington stepped out of bounds and touched a kickoff, I learned that this was considered a kickoff out of bounds and placed the ball at the 40-yard line. The first time I saw a fumble out of the end zone called a touchback, I was as befuddled by the rule as most football fans (though not Robby Sabo, who told me he believes the rule makes sense).
If I struggled with these NFL concepts, I assume others do, too. That’s why I figured I’d clarify something that constantly made me scratch my head: what makes a formation legal or illegal?
Line of scrimmage rules: Offense
At the snap, the offense must comply with the following rules.
- Seven or more players on the line of scrimmage
- Eligible receivers must be on both ends of the line, and all of the players on the line between them must be ineligible receivers
- it is illegal to leave an ineligible receiver uncovered on either side of the line
- No player may be out of bounds
- No player with an eligible number (between 1-49 and 80-89) may report as eligible and line up outside the tackle box
What does eligible mean?
There are many complicated rules about eligible vs. ineligible receivers. Here are the basics of ineligible receivers.
- Players who are not at either end of the line of scrimmage or at least one yard behind it when the ball is snapped.
- Players wearing the numbers 50-79 unless they report eligible to the referee and line up in an eligible spot. In other words, offensive linemen are ineligible unless they report to the referee and line up outside the tackle box.
- An offensive player who went out of bounds before or during a pass without being illegally pushed there.
- a quarterback under center in the T-formation, unless he moves to an eligible spot and stands there for at least one second before the snap.
Examples
Take a look at this New York Jets formation pre-snap. It is a standard legal formation.
The five offensive linemen are ineligible, as usual.
When the rule says that eligible players must be on both ends of the line, it means there must be an eligible receiver on the line of scrimmage on each side of the five ineligible receivers. Between those two players, all other players on the line must be ineligible.
Malik Taylor (No. 86, slot left) is on the line of scrimmage, as is C.J. Uzomah (No. 87, slot right). Between them, all the other players are the offensive linemen, who are ineligible. Garrett Wilson (No. 17, outside left) and Allen Lazard (No. 10, outside right) are off the line of scrimmage.
The Jets were called for two illegal formation penalties in 2023. Here’s why.
On this play, Xavier Gipson (No. 82, right) is on the line of scrimmage, as is Allen Lazard (No. 10, left). That means all eligible receivers between them must be off the line of scrimmage.
However, Jeremy Ruckert (No. 89), lined up outside the left tackle, is also on the line. For this formation to be legal, either Ruckert or Lazard should have lined up off the line of scrimmage. (The flag was called on Ruckert, but it was Lazard who covered up Ruckert, not the other way around.)
On this play, Jason Brownlee (No. 16, right) lined up off the line of scrimmage, as did tight end Kenny Yeboah (No. 88). Normally, you will see a receiver communicate with the tight end to move up to the line. This formation was illegal, as neither Brownlee nor Yeboah was on the line of scrimmage.
On the left side of the line, you can see Garrett Wilson line up on the line (to cover the left tackle) and Xavier Gipson off the line.
Lions vs. Cowboys debacle
In December 2023, the Lions and Cowboys faced off in a game that had implications for NFC playoff seeding. The Cowboys held a 20-13 lead, but the Lions scored a touchdown with 23 seconds remaining to cut the lead to one. They decided to go for two to try to take the lead. They came out in a strange formation.
The Lions had seven offensive linemen on the field on this play. Since there was no receiver on the line of scrimmage on the left side of the line, the player lined up in the left tackle spot, Taylor Decker (No. 68), must have been eligible for the formation to be legal. Otherwise, there was no one covering up the tackle on the left side.
Jared Goff threw the pass to Decker, who caught it for an apparent conversion. However, the referees called illegal touching on Decker, claiming he did not report as an eligible receiver. Therefore, he was not allowed to touch the pass. The formation was also illegal with no eligible receiver on the line of scrimmage covering up the tackle.
After the game, Decker claimed that he did report eligible along with Dan Skipper, the extra offensive lineman who lined up off the line of scrimmage on the right side. The referees may not have heard him or misunderstood because they were unaccustomed to having two offensive linemen report eligible on the same play.
(The weirdest part of this formation was that Goff lined up under the regular center, but he was technically the left guard in this formation. That may have tripped up the referees, too.)
Either way, if the referee did not announce No. 68 as eligible, the Lions should have known he was not eligible. Still, it was likely a gaffe by the officials in a pivotal moment. Detroit tried the two-pointer again from the seven-yard line and failed.
2014 Patriots rule
In 2014, The Hoodie’s rule manipulation led to a controversial playoff victory over the Ravens. The Patriots ran odd formations in which they played an ineligible wide receiver lined up at the regular wide receiver spot and an eligible wide receiver at the regular offensive tackle spot.
This confused the Ravens, as they thought the player at the tackle spot was ineligible (as usual) and the receiver was eligible (as usual). The Patriots then threw to the eligible receiver (No. 47) who had lined up in the offensive tackle spot and was wide open.
The NFL then changed the rules, forcing players with the numbers 1-49 or 80-89 to line up inside the tackle box if ineligible. The purpose of formation rules is to prevent tricky plays like these and level the playing field for the defense.
Defensive formations
On defense, legal formations are relevant only on kick and punt plays.
- In punt, field goal, and extra point formations, a defensive player within one yard of the line of scrimmage must have his entire body outside the snapper’s shoulder pads at the snap.
- In field goal and extra point formations, there may be no more than six defensive players on the line of scrimmage on either side of the long snapper at the snap.
The Giants thought Will McDonald’s body was not outside the snapper’s shoulder pads on Graham Gano’s missed field goal. McDonald jumped over the center and likely caused Gano to change the kick’s trajectory.
As you can see, it’s extremely close. Is McDonald just inside the shoulder pads or just outside them? The referees rarely call this unless it’s more blatant.
