If a player’s ball at rest might have moved but this is not “known or virtually certain”, it is treated as not having moved and must be played as it lies. But if the ball has moved, the “known or virtually certain” standard will also apply to all questions of fact about why a ball at rest moved. This means it must be at least 95% certain that:
- A player, opponent or outside influence caused the ball to move.
- Otherwise it will be assumed that natural forces caused it to move.
Reasons for change
The weight of the evidence test under the current Rules is often difficult to apply in ball moved situations:
- Many competing factors need to be balanced, such as what the player did near the ball, the lapse of time before the ball moved, the lie of the ball, the slope and other course conditions near the ball and the presence of wind or weather conditions, and there is no prescribed way of prioritising or balancing these factors.
- Since “known or virtually certain” means more than just possible or probable, this standard will be simpler to apply because it will eliminate most “close calls” where it is hard to know for sure why the ball moved.
Using the “known or virtually certain” standard will fit well with the new Rule 13.2 that will eliminate the penalty for accidentally causing a ball to move on the putting green:
- The primary reason for eliminating that penalty is that it is often particularly difficult to decide why a ball moved on the putting green.
- Given those particular difficulties, using the “known or virtually certain” standard will be more clear-cut and easier to apply. It will help avoid the risk of players being penalised for playing from a wrong place, for example, by replacing the ball when it should have been played as it lies, or vice versa. It also creates consistency because the penalty for accidentally causing the ball to move was removed because of the difficulty of balancing factors.
This Rule change also means that only the single standard of “known or virtually certain” will be used for all ball moved questions, rather than the situation under the current Rules where different standards apply in deciding whether an outside influence moved a ball or whether the player or opponent did so.