ENGLEWOOD, Colo. — The NFL’s new “illegal use of the helmet” rule is giving the entire league a headache.

Players and coaches across the country have been baffled by the rule. Confused and frustrated by the calls being made across the preseason.

“It is a foul if a player lowers his head to initiate and make contact with his helmet against an opponent,” the rule states. “Contact does not have to be to an opponent’s head or neck area—lowering the head and initiating contact to an opponent’s torso, hips, and lower body, is also a foul. The rule applies to all players at all times.”

As the preseason has drawn on, the flags have been flying left and right for this call. It’s not uncommon, though, for NFL Officials to over-emphasize a call in the preseason to help players adjust. It’s like putting vinegar on a kid’s fingernails to try and break their habit of biting them.

There’s just one problem, a disturbing trend is showing up. In trying to call the new 15-yard penalty liberally, the officials are revealing the biggest problem with the foul itself. The problem is that, at the speed in which the NFL game is played, it’s really, really hard for an official to tell if contact is being initiated with the helmet or if it’s being initiated with the shoulder.

“It’s really gray right now,” Broncos head coach Vance Joseph admitted.

What’s happening is that players and coaching aren’t learning the new rule by the preseason emphasis, they are becoming more confused because the officials keep calling it wrong.

On Saturday night, as 6-foot-1, 190-pound Broncos cornerback Issac Yiadom approached 6-foot-6, 270-pound tight end Adam Shaheen, he did what any corner is taught to do when tackling a big target, he did everything he could to be the lower man so as to take out the legs. Even though he appeared to lead with his right shoulder pad, he was still called.

“With Issac’s, his head was down, but it didn’t hit the body, it was placed to the side of the receiver and it was his shoulder on the body, not a foul,” Joseph said.

Later, Bears corner Kyle Fuller found himself in a very similar situation with Broncos fullback Andy Janovich as the ball carrier.

“Even Fuller’s on Andy, it was head down, but shoulder hit the body, not a foul,” Joseph said, showing his problem was not only with calls that hurt his team.

In fact, in watching the replay, if there was a flag to be thrown, you would likely conclude that it should have been on Janovich, not Fuller. Joseph wasn’t even convinced of that, though.

“I don’t know, I mean, he’s defending himself,” the head coach explained. “Fuller is a corner coming to hit him, what’s he going to do? Keep his head up and take it in the chin? He naturally drops his shoulder, the head is attached to the shoulder so it’s going to drop. We have to be careful and we have to use common sense, right?”

“We know what spearing looks like, so call spearing,” he concluded. “Don’t call good football tackles. Call it when it’s spearing, if it’s not spearing, don’t call it.”

It’s hard enough for players to adjust to this new rule, but it’s going to be a real mess if the referees can’t even call it right, and that’s what we’re seeing right now.

When Broncos safety Will Parks asked a ref how they were supposed to avoid the call, he wasn’t told to keep his eyes up or to make sure his helmet is off to the side, he was told, “Try to hit him with your chest first.” The problem with that—other than being contradictory to just about every tackling drill—is that it gives the offensive player all of the leverage. If you make contact with your chest first, you can all but guarantee you’re going to be the one on your back.

At this point, we can still live in a world where the problem is that the refs are over-calling the foul because it’s the preseason, but if we get to Week 1 and there’s yellow on the field every time a player leads with his shoulder, things are going to get ugly.