Illustration: Jim Cooke (GMG)

Last month, the NFL approved a rule that strictly defines what players are permitted to do with their helmets, in the name of player safety. It's pretty much a given that the rule is going to create some chaos, at least initially. But it might also portend a fundamental change in how the game is played.

The rule is narrowly drawn, in an attempt to leave little room for ambiguity, which has been something of a problem with college football's decade-old targeting rule. The NFL's rule now reads, with remarkable simplicity, "It is a foul if a player lowers his head to initiate and make contact with his helmet against an opponent."

It will be classified as unnecessary roughness, which carries a 15-yard penalty. The only additional explanation provided by the rule book is this, with strike-throughs denoting the language that's been excised:

So: No player can lower his head to make contact, and using any part of a helmet to "butt, spear, or ram an opponent" is verboten, regardless of intent or impact. As for what might constitute an ejection…

For additional clarity, the league put out a video that shows different plays that will be deemed illegal, along with examples of hits that will warrant an ejection, which will be subject to video reviews to be done by the centralized command center in New York City:

With this rule, the NFL is attempting to avoid the over-legislated confusion it created with all the additions made through the years to the catch rule, which never could keep up with the infinite potential movements of the human body. By drawing the helmet rule so narrowly, the NFL is trying to discourage the sort of plays like the one that injured Steelers linebacker Ryan Shazier last year. But depending on how strictly it's enforced, it might also prohibit any number of prosaic football maneuvers, too. Offensive players with the ball often lead with their helmets to either fight for extra yardage or to brace themselves for oncoming contact. This is especially true for quarterback sneaks. And on every play, offensive and defensive linemen tend to smack helmets as a matter of course.

Jim Daopoulos, a former NFL official who also spent 12 years supervising the officials, has no idea how the officials are even expected to enforce the rule. "It's going to be a tough situation for them to police," Daopoulos told me.

Dean Blandino, another former head of officiating now working as a Fox Sports rules analyst, agreed. "The challenge with this rule, just like the crown-of-the-helmet rule that went in in 2013, is how can the official at full-speed officiate that consistently?"

The simple language of this year's helmet rule replaces the 2013 crown-of-the-helmet rule, which had read as follows:

The crown-of-the-helmet rule was "something that really wasn't a point of emphasis," Blandino said. "It wasn't officiated." That this year's rule will supersede it can be read as a signal that the league intends to emphasize the rule's application. But how? Helmets get lowered to initiate contact on pretty much every play.

"The game happens so fast," Blandino said. "So they're going to have to differentiate between whether it's an incidental contact, or, say it's a running back that's trying to protect himself and brace for contact versus actually delivering a blow with the helmet."

The officials have a process that will allow them to educate themselves on the rule's application, Blandino explained. Some of that will transpire during the annual officials' clinic scheduled for next month. Some will take place during the preseason games, when there likely will be lots of flags thrown, just as there were back in 2014, when tighter rules against illegal contact and defensive holding went into effect. And some of that will probably bleed into the regular season. The officials will largely be learning on the fly, and flagging—at least initially—only the most egregious examples.

"They have a couple of clear-cut examples, and there's going to be some gray area, and I think what the officials will be told is if there's a question, don't throw your flag and then they'll deal with it during the week, and they can certainly fine the players and then use that as examples, to show the officials, 'Hey this is a foul,'" Blandino said.

Enforcement at the line of scrimmage is what's likely to create the most consternation. In a presentation to the media at last month's league meetings, NFL senior vice president for officiating Al Riveron told reporters this:

"This is the thing that's going to make officiating so difficult," Daopoulos told me. "We know the situations where a player just basically launches and leads with his helmet and hits [a ballcarrier]—you can understand, that happens sometimes out there. But when you have two linemen—and I was an umpire, which basically was behind the defensive line—they're like two rams charging each other. Now are you going to eject both players? I just don't seem to feel that's very feasible. I think they're going to do a lot of discussing over the next couple of months."

Said Blandino: "They haven't really touched on the linemen yet, at least in the videos; I think they're still trying to figure that out, and I think that's going to be tough to do, with all the contact that happens in close line play."

Daopoulos also wondered about the video review process for ejections. Last year, we saw how central command's interpretation of the catch rule only sowed more confusion. It's not hard to envision something similar happening with the helmet rule. "I think they're going down a slippery slope with this," Daopoulos said. "You've got guys up in the replay booth that have never been on a football field in the NFL making those types of decisions. I understand that they know their stuff about replay and all, but you've got to have a feel for the game. When things happen out there and they happen so quickly, it's hard to differentiate between, 'Hey, that's a foul, and I'm going to eject him,' or, 'Man, that's just a good football play.'"

Geoff Schwartz, who played eight seasons as an NFL offensive lineman, sees the helmet rule as the possible start of something that could completely change the game. Yes, past rule changes—to protect quarterbacks and defenseless receivers, plus the crown-of-the-helmet rule—were greeted with similar reactions, and the sky never fell. But if the league is indeed intent on enforcing a rule against leading with the helmet when linemen collide? That's new territory entirely.

"I think we're eventually going to go to where there's not going to be a three-point stance anymore," Schwartz told me. "Everyone's just going to have to be up, because that seems to be the way that they want this to go. I just worry that that change will fundamentally change the game."

Mike Florio of Pro Football Talk has made this point, too. The three-point stance has been a fundamental part of line play since it was first introduced in the late 19th century. As Schwartz explained, the stance is used because it helps both offensive and defensive linemen create leverage and power. But firing up out of a three-point stance invariably involves using one's helmet to either power through an opponent or holding one's ground. Without it, a whole lot changes—including the likelihood of the sub-concussive blows that studies have shown can contribute to long-term brain trauma. But the game itself will have to change, too.

"Run blocking would be supremely easier if the defense was not in a three-point stance," Schwartz said. "It would just lead to more scoring, which is what they want."

The NFL has openly pondered the possibility of eliminating the three-point stance in the past. As far back as February 2010, in the wake of the league being shamed by Congress for its distortion of the science of brain trauma, commissioner Roger Goodell mused out loud about banning it. Those were heady days; the league was staring at the certainty of litigation and looking to slough as much liability as possible onto the players themselves. That's still true, but players today are much more aware of the risks and more willing to self-report head injuries than they might have been in the past. "There's no way you can play now and claim you didn't know that there are possible side effects of playing in the NFL, or playing college football, or whatever it may be," Schwartz said.

The game might already be changing anyway. This decade has seen the gradual development of pass-heavy offenses, along with the proliferation of spreading the field, pre-snap motion, read-options, run-pass options, mesh concepts, and lots of play-action. The NFL is becoming more and more wide open because that's the way the high school and college games that are developing its players has been trending. Last year's Super Bowl may have been the best example yet of the direction of modern football.

"Look, we also always do complain every time there's a rule change, and the game just continues to play on," Schwartz said. "So maybe we're freaking out for no reason."