Bill Belichick was in Lincoln recently, speaking at the Nebraska coaches clinic.
I always liked what John Madden had to say about Vince Lombardi in his book. He went to a Lombardi clinic and Lombardi spent 4 hours on ONE play, the Green Bay power sweep.
If you’ve never seen the Lombardi motivation film, “Second Effort”, it is still worth finding and watching, even though it’s over 50 years old.