As Bears first-round pick Roquan Smith continues his holdout over contract language regarding the new NFL helmet-contact rule, his teammates will be the first players to put the rule to the test.

Nobody is quite sure how it will play out.

“It’s going to be an extremely hard play to officiate, other than the super obvious,” defensive coordinator Vic Fangio said Tuesday after the Bears’ final practice before the Hall of Fame Game against the Ravens on Thursday

The new rule makes it illegal for players on offense and defense to lower their heads and initiate contact with their helmets. An infraction will result in a 15-yard penalty. A player can also be ejected if he lowers his helmet to establish a linear body posture before making contact, if he had an unobstructed path to his opponent and if the contact was clearly avoidable.

Fangio said the Bears have been teaching the new rule in meetings and showing a lot of video of plays that would be affected. They have had some live tackling sessions during training camp, but they haven’t had a ton of opportunities to make sure they are avoiding the types of plays that will be penalized.

“There are some plays that will be hard to adjust,” Fangio said. “We’ll just have to keep working on it. One of the most non-football rules ever put into football was the 5-yard illegal contact rule. If coaches from the ’60s rose from the dead today, they would want to go back in their grave with that rule. And we’ve adjusted. I think they’ll eventually adjust.”

Fangio and special teams coordinator Chris Tabor expect officials will throw many flags in exhibition games as teams and officials adjust, and the Bears will look at penalties as teaching moments for the regular season.

“We’re going to have to change a little bit as we go throughout the year,” Tabor said. “And as penalties arise from that play, I think it will just be ‘teach tape’ for us in what they can and can’t do.”

Despite Fangio’s doubts about regulation of the rule, he understands the reasoning behind the change.

“Everything to improve the safety of the game is good,” Fangio said. “And the motives behind the rule are good. I’m just not sure in some cases if it’s feasible.”

As for Smith, who is seeking financial protection from the Bears should he be ejected under the new rule, Fangio didn’t bite on a question asking if he understood players’ and agents’ concerns.

“I’m not going to give you a line that you’re going to print,” he said.

ckane@chicagotribune.com

Twitter @ChiTribKane

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