Let's start with something many of us can agree on: Malcolm Jenkins walloped Brandin Cooks in the Super Bowl.
It's a famous hit, and a vicious one. No flag was thrown, but the tens of millions of fans who saw it wouldn't have been surprised if there was one. It was a borderline play, the kind that should serve as a benchmark as the NFL implements its new use-of-the-helmet policy.
Under the new rules, which are meant to completely eliminate crown-of-helmet contact, the famous Jenkins-Cooks collision would appear to be a good template for an unnecessary roughness penalty.