Players tune out when they don’t know the reasons that film work is being done. They tune out when they’re not being taught.
They screw up when either they don’t know their assignments, don’t know what they should’ve done in that particular situation, nor understand why they need to do what they’re supposed to do. I’m not talking about reviewing guys getting their asses kicked physical. Reviewing blown assignments, bad angles, and piss poor effort is necessary, worthwhile, and will yield results.
Knowing how their screwup affects other aspects of the team and the game plan is essential to correcting performance. It further enables guys to fill-in at other positions, which they can’t do if they haven’t done adequate film work.
Lance Briggs and James Harrison had simple freaking jobs, containing the run and rush the passer. They were really involved and complex coverages so I can see why these guys got bored. When you have a relatively young defense and complex games, film work as essential as tedious as it may be. As part of the discipline that separates good teams from grade teams.
And I don’t have to do any research on the subject. I played and I coached. Good coaches know how to hold players accountable. Bad ones don’t.