Between the golf drive and the tennis ground stroke, which is an open skill and which is a closed skill?
The golf drive is relatively unchanging. The ball is still, not moving – so it is a closed skill. In tennis, you hit a ground stroke, either a forehand or a backhand, when the ball has been hit to you. The ball is moving, so the conditions from one stroke to another are constantly changing. That makes tennis ground strokes open skills.