By Tim Kilty
While it is sometimes dangerous to deal in generalities when it comes to The Rules of Golf, when a ball at rest and in play is moved by anything other that a stroke, it must be replaced (Rule 18). If the ball moved after the player has begun his stroke or the backward movement of the club for the stroke and the stroke is made, there is no penalty and the ball must played as it lies. However, the player is not exempt from a penalty if the player somehow moved the ball (18-2a) and/or the ball moved after address (18-2b). Also see Rule 14-5, Playing Moving Ball.
During the recent Players Championship, on a very windy day there were two interesting scenarios concerning a ball being moved by the wind, which is not an outside agency. In the first instance as the player was about to mark and lift the ball on the putting green, the ball moved prior to the completion of the act of marking. No problem,as the ball had not been marked as defined in the rules. Fortunately the ball rolled about 16 feet closer to the hole! See Rule 20-1 and 20-3. In the second situation the player, Boo Weekley, was not as fortunate. Boo addressed his putt, i.e. took has stance and grounded his putter, and his ball subsequently moved. In this situation, the player is deemed to have caused the ball to move, whether he did so or not. See Rule18-2b. Boo was assessed a one stroke penalty and the ball was replaced on the original spot.
Continuing with Rule 18-2 incidents at the Players Championship, about 10 years ago, Davis Love III was in contention, playing the famed 17th hole. When taking a practice swing for his putt, he accidentally struck his ball in play, moving it a few inches. He did not replace the ball, holing out with his next stroke. Davis thought he had incurred a one stroke penalty and included that penalty in his score for 17. After completing his round and signing his score card, he was advised that since he did not replace his ball on 17, he incurred the general penalty for a violation of Rule 18-2, two strokes. As a result he signed for a score that was lower than actually made. Unfortunately, this is a disqualification penalty (Rule6-6d) Wrong Score for Hole. As Davis would have had a top 10 finish, this was a very expensive lesson!