Homer Kelley revolutionized golf instruction for many professionals. To him, one of the secrets of golf was what he called ''clubhead lag.'' It might also be called drag.
In a good swing the clubhead on the downswing lags behind the hands (and behind the body) until just before ''the release.'' That is, until the hands are approaching the ball, maybe in line with the right thigh.
It is vital therefore to establish lag. One must have some key, some pressure point, some feel which ensures that the clubhead does indeed lag behind the hands.
Homer's own key point was the trigger-finger of the right hand. So was that of the great English golfer, writer, photographer, and teacher Henry Cotton.
But this is not the case for everyone. Some drag the club down with the last three fingers of the left hand. A few drag with the left upper arm, others with the left hip.
What one does matters little, so long as one indeed establishes lag. You must tow the clubhead behind you.