No rule has caused so much consternation to the USGA and R&A as Rule 18-2. Rule 18-2 states if a player causes a ball to move, the player incurs a penalty of one stroke. In the end a rules official must determine what caused the ball to move, and there’s the rub.
The interpretation of Rule 18-2 caused what many describe as a fiasco at the 2016 U.S. Open. Dustin Johnson’s ball moved on the 5th green, and it had to be determined what caused the ball to move. Johnson declared he had not caused the ball to move. On the 12th tee, Johnson was informed he may be assessed a one stroke penalty. The question of the penalty became moot when Johnson won by four strokes. The USGA ruled that absent any other suspects (wind, gravity), Johnson was guilty. The one stroke penalty only reduced Johnson's winning margin to three strokes. If Johnson had tied with another player, would the USGA have assessed a penalty? Probably not. The USGA looked bad enough without deciding the outcome of a major championship on the subjective judgment of a panel of rules officials. The eighteen hole playoff would have been held on Monday.
The 2015 Open Championship encountered another problem with Rule 18-2. Louie Oosthuizen addressed a tap-in putt, but a gust of wind started the ball moving and it did not stop until it was five feet away from the hole. At that point, play was suspended, but too late to help Oosthuizen. He had to play from the further distance.
The problem inherent in Rule 18-2 is that it does not make a distinction between a ball on or off the green. With today’s fast greens, it is much more likely a ball can be moved by wind or gravity. But whether wind, gravity, or the player is the culprit is still difficult to discern. To bring more equity to the problem, a rule change (also suggested by others) could make a ball on the green not in play if has been addressed or marked. It is only in play after the ball has been struck by a stroke. Under this rule change, if the ball moves for any reason other than a stroke, it must be replaced with no penalty. This rule change meets the following requirements of a good rule.
Clarity – No need to call in an official if the ball moves on the green after it has been marked or addressed. Simply replace it. The adoption of this rule would eliminate many Decisions on when a penalty should be assessed. It does bifurcate the rule depending on whether the ball is on the green or elsewhere. This is reasonable, however. Through the green, a player could move his ball in an attempt to remove loose impediments around his ball. He should be penalized since the removal of the impediment would improve his lie. On the green, however, the player is allowed to remove loose impediments without penalty. In other words, the Rules already differentiate between a ball on the green and a ball through the green.
In determining whether a ball has moved a player is given some leeway in the rules. If the ball moves by an amount not reasonably discernible le to the naked eye, a player’s determination that the ball has not moved will be deemed conclusive, even if that determination is later shown to be incorrect through the use of sophisticated technology (Decision 18/4). The revised rule would eliminate this Decision, make the outcome independent of the leniency of the rules official and minimize the number of call-ins from Rules Mavens who believe they detected ball movement.
Fairness – The revised rule tends to minimize luck in determining tournament outcomes. If the wind blows a ball that has been addressed or marked off the green or in the hole, the player would not be punished or rewarded for such random acts of nature.
Proportionality –The one stroke penalty for a player inadvertently moving his ball on the green appears to be disproportionate. Currently, a player is assigned the same penalty for 1) dropping his marker on his ball and causing it to move or 2) hitting a ball into a water hazard. The latter action is the result of a bad swing and/or judgment and should be penalized. The first action is due to carelessness. A player gains no advantage if he replaces his ball after inadvertently causing it to move on the green. True, the current penalty of one stroke acts as a deterrent to such carelessness. But any benefit from reducing the frequency of such behavior is more than offset by the elimination of disputes over what caused the ball to move.
Any change in the Rules needs to be seriously vetted. There may be unintended consequences of having a ball on the green considered out-of-play. Testimony should be taken from those most affected by Rule 18-2 (i.e., Tour Players). USGA and PGA Tour officials responsible for making the call of when a ball has moved also need a voice. Rules changes follow Newton’s First Law: A rule at rest tends to stay at rest. Without a demand for change from players and officials, Rule 18-2 will be cut and pasted into the next edition of the Rules of Golf for the foreseeable future.
 That same leeway test is not given when a player touches the ground in a hazard. In the 2016 Women’s U.S Open, Anna Nordqvuist touched the sand with her club and was given a two-stroke penalty. A strong argument could be made that the violation was not apparent to the naked eye. No one noticed the small grain of sand take a tumble until Fox, using sophisticated technology, zoomed in on her address of the ball. Should the USGA be consistent in its Rules and apply the same standards concerning sophisticated technology to ”ball moved” and “touching the ground?” It is a debatable question, but one that has never been publically addressed by the USGA.