Relax the right arm to keep the driver down the line
The coach tells the student that letting the right arm relax through the swing keeps the club down the line, whereas a stiff right arm can send it a little higher. He notes players often stiffen the right arm when they consciously try to keep it in, which induces that slight lift.
Channel: PorzakGolf
Watch official source at 1:45Why this context matters
Coach working with a student on a driver miss to the right/high on the face.