On the 5th hole, during the final round of the 2016 U.S. Open Championship, eventual winner Dustin Johnson was making practice strokes next to his 3 footer for par when the ball moved. Dustin had not yet addressed the ball and quickly called in a rules official. Both had determined there was no penalty. On the 12th tee box, USGA officials let Dustin know that he “may” be penalized but would discuss after the round. Dustin was eventually penalized. Luckily it did not affect him winning the championship.
The original Rule 18-2b
In the 2012 rule book, Rule 18-2b assigned an automatic penalty if the golf ball moved after the player addressed it. A small exception was allowed if it was certain the player did not cause the ball to move.
2016 rules
As of 2016 the rule has changed to be dependent on the answer to one simple question: Did the player cause the golf ball to move?
If yes, a 1 stroke penalty is applied and the player has to replace it.
If no, there is no penalty and the ball is to be played from its new location.
In Dustin’s case the USGA reviewed video evidence of his actions, the time between those actions and the movement of the ball, the lie of the ball, and the course and weather conditions, and determined that Dustin “more likely than not” caused his ball to move.
What to know about golf Rule 18-2
The takeaway for competitive golfers that do not have access to video review is to rely on judgment. If you feel you “more likely than not” caused your ball to move, that’s a penalty. If not, play on. When in doubt, use Rule 3-3. If you’re unfamiliar with Rule 3-3, a rule book is strongly recommended!