First 2 Games down

[PaulJak]

Correct me if I'm wrong, but in high school restrictions for B don't start until the ball is thrown (unlike A where they start at the snap). Unless B is holding the TE or tackling him I've got nothing if they legally block him to the ground.

I don't recall a rule that says once somebody is obviously a receiver or 5 yards down field (a popular cry of coaches). B can chuck and legally block until the ball is thrown. And then its only OPI if the ball is thrown toward that receiver. Do I think this creates an advantage for the wise defense to bump receivers on their routes, yes, but I don't know of rule support for calling "obstruction of a route" (before a pass is thrown) in high school.