My heart is with the downtrodden defensive players in the NFL, who have been threatened with suspensions and stupendous fines if they hit offensive players with their helmets. From their point of view, the league is spitting on them to protect its stars, the most expensive offensive players.
In the Eagles/Titans game today, late in the third quarter, an Eagle took the Titans' punt and accelerated through the pack in a fine runback. Soon he had only one offensive player to beat. He put his helmet down and crashed into that Titan, helmet to helmet. No foul was called! The announcers did not even notice that an offensive player had initiated a helmet hit.