The new helmet rule is an attempt by the league to make the game safer. In theory, everyone agrees this is a good idea. In practice, it's unclear how officials will implement the rule. And if Thursday night's Hall of Fame game was any indication, there's far more ambiguity than clarity on what is and isn't a penalty.

This is a huge concern and Redskins safety D.J. Swearinger and 49ers cornerback Richard Sherman have weighed in on the potential problems.

"I guess not hit a guy when he ducks so I guess we just gotta aim for the knees," Swearinger earlier this week.

Sherman added: "They'll see how ridiculous it is, once they make the refs call it. It's going to be worse than holding, worse than the catch rule. On a good form tackle, guys will lead with their shoulder pads, but you bring your head. It's going to be a disaster."

But not every player feels this way; Rams cornerback Aqib Talib thinks the new rule is a good thing.

"They're trying to have guys healthy when they retire," Talib said, via ESPN.com. "So it's good for the tackler, it's good for the offensive guy."

Talib, who is entering 11th season, also points out that rules changes are nothing new.

"They put an emphasis on something every year, so we've just go to adjust," he said. "That's why we're pros. We adjust on the fly, we adapt to all kinds of situations."

For now, confusion about the new rule remains. In the Hall of Fame game, Ravens safety Bennett Jackson was flagged for violating the helmet rule -- even though his tackle could be better described as "textbook" -- but the over-officiating was by design, at least in the preseason.

"I feel like they're trying to harp on it a lot more in preseason, so they're going to throw flags even on times when it's not necessarily head to head, just to make people aware of it," Jackson said. "I spoke to the ref. He even said, 'Hey, it's preseason, we got to throw the flag.'"

NFL officials has four weeks to find the right balance between safety and consistency. Whether they can do it is another matter.