Over the past few years, the rule changes in the NFL have all benefited the offense. Rules that force defensive backs to be less aggressive on wideouts, or refs being strict on QBs getting hit after they throw the ball. Well now there is something that benefits the defensive side of the ball. The refs are now watching plays behind the QB, and during the preseason holding penalties are up, the angle the refs are at now does not allow O-lineman to hold like they do on every play. I think it will take a year for offensive lineman to adjust to this change, and this will benefit the defense.