Anyone understand what is pass interference?

[techtim72]

As I watch football now, I have no idea what constitutes pass interference. I know about turning the head, common right to the ball, etc., but all I see is tremendous inconsistency in the calls. It seems like the referees in general are allowing more aggressive contact, perhaps in response to the explosion in offensive football and to what seems like increasing size disparity between receivers and defenders. Years ago the call was made with even the most minor of contact. Not sure what turned it around, but I remember a few Super Bowls where New England's defensive backs mauled the receivers without penalty. I can also remember more than a few games which turned on very technical assessments of replays. Now it seems like even the announcers don't know what the call should be. Northwestern benefited from a non-call yesterday but I have no doubt that the calls went both ways. McGowan, for example, was called for what seemed to me to be a minor push-off on a potentially big gain.

 

[Fitz51]

It's when the referees put their hands up, palms facing out, and point at one of the teams. They seem to just do it whenever they'd like.