Take the club back and down on the same plane
The instructor says hanging the arms below the shoulders means the club must lift into impact, making solid contact with the clubface harder. For a single-plane swing, he says to set up correctly and take the club back and down on the exact same plane; doing so makes it easier to reach impact and hit the middle of the face.
Channel: Todd Graves
Watch official source at 0:26Why this context matters
Part of a short lesson pitching why the single plane swing improves ball-striking.