Between the fans, players, coaches, and seemingly even the referees, no one appears to know full well where the line is drawn with regards to the new helmet rule in the NFL. Count Denver Broncos head coach Vance Joseph among the many being left stumped by this new rule that prohibits players from using their helmet to hit an opposing player.

While speaking to reporters on Monday, Joseph tried to apply reason to why the rule has become a polarizing anecdote in the preseason, but also said that how it’s being called and interpreted is very confusing to many (via ProFootballTalk).

“It’s really gray right now,” Broncos coach Vance Joseph told reporters on Monday regarding the new rule. “I think they’re calling it conservatively because they want to get it right, I think. They want to change the behavior. The problem I’m having with the call right now is it’s been bang-bang plays, and it’s hard to tell if the head is hitting the body. That’s the rule, right? It’s not about if the hit is down. If it it’s the body, that’s the penalty.”

Teams were introduced to the rule and educated about it by league officials during training camps, but it’s only now that Joseph and the rest of the coaches are getting a first-hand look at how it’s being applied. Joseph also understands how hard it might be for officials to call the infraction, considering the thin line between what’s acceptable and what’s not.

“The foul is when the head hits the body. That’s what we have to be careful of, but it’s hard to tell, because you tackle with your shoulder but it’s led by the head. It’s hard to officiate that really cleanly. We’ll see how it shakes out, but right now, it’s gray for us and the players.”

Will the uproar cause the NFL to modify the rule? That’s something that remains to be seen, but it’s undeniable that not a few want it in play.