Getty Images

Thursday night’s opening game between the Eagles and Falcons featured 28 penalty flags, but none of them were for violations of the league’s new rule governing the use of the helmet.

None of the games on Sunday involved that many flags, but the lack of outsize impact from the rule change was the same. Kevin Seifert of ESPN.com reports that there was only one penalty for lowering the head to initiate contact across 13 games on Sunday.

Chiefs safety Ron Parker was flagged for a hit on Chargers running back Austin Ekeler in the first quarter of Kansas City’s win, but the rest of the games were free of flags for violations of the new rule. That includes Bengals safety Shawn Williams‘ ejection for a hit on Colts quarterback Andrew Luck as the league deemed that an unnecessary roughness foul rather than a helmet foul.

The lack of penalties continues the trend that started midway through the preseason when the NFL clarified the rule did not cover inadvertent contact and flags stopped flying as regularly as they had in the first two weeks of exhibition games.