Question:- Before playing from the teeing ground, a player took a practice swing, in the course of which he accidentally struck and moved the teed ball with his club. Did the player play a stroke or incur a penalty?
Answer:-The player did not make a stroke (see Definition of 'Stroke'). Since the ball was not in play (see Definition of 'Ball' in 'Play') he incurred no penalty under Rule 18-2a. The player must put a ball into play from the teeing ground.
Definition of Teeing Ground
It is the rectangular area two club lengths in depth, the front and the sides of which are defined by the outside limits of the two tee-markers. A ball is outside the teeing ground when all of it lies outside the teeing ground. Penalty from playing outside the teeing ground is 2 shots and a ball must be played from within the teeing ground