Editor's note: This story was originally published in May 2014
PGA Tour officials required slow-motion replay and high-definition television screens to determine whether Justin Rose's ball moved as he was about to address it Saturday during third-round action at The Players Championship. Did the ball move when he was lining up for his chip? Officials first docked him two strokes, then changed their minds Sunday morning, citing the new decision that went into effect on Jan. 1 dealing with situations "not easily discernible to the naked eye."
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But when you're playing a round at your local course, it's up to you and your partners to know Rule 18-2b and its consequences. According to Bryan Jones, co-vice chairman of the PGA Rules Committee, the rule is really pretty simple to remember: "Address the ball, ball moves, replace the ball, one-stroke penalty."
Here's the actual language from the rule book concerning what to do in that specific situation:
"If a player’s ball in play moves after he has addressed it (other than as a result of a stroke), the player is deemed to have moved the ball and incurs a penalty of one stroke.
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"The ball must be replaced, unless the movement of the ball occurs after the player has begun the stroke or the backward movement of the club for the stroke and the stroke is made.
"Exception: If it is known or virtually certain that the player did not cause his ball to move, Rule 18-2b does not apply."
For example, you set your club behind the ball and it rolls from its position -- whether you touched it or not -- that's a violation of Rule 18-2b. That's because "the player is 'deemed' to have caused this movement," Jones said.
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So whether you're playing stroke play or match play, that's a one-stroke penalty. But what does the rule mean by "replacing" the ball? Jones said you have two options, depending on the situation.
"Remember, replace can mean place or drop," Jones said. "If the previous location of the ball is precisely known, it is placed back in that spot. If not, it is dropped. The exception is on the putting green, where it is always placed."
Interestingly enough, if the ball moves because of gravity, it is considered a violation of Rule 18-2b. Replace the ball, take the penalty. If the ball rolls backwards at address and is stopped by the clubhead, that's also covered under Rule 18-2b. Replace the ball, take the penalty.
There are some exceptions. For example, if the ball moves in a bunker without being affected by the player's stance or approach to the ball, that's not a penalty. And if the ball only wobbles and remains in its original position, Decision 18/2 says there's no penalty and no need to replace. We've seen "oscillation" brought up in tournament play in the past.
Jones calls Rule 18-2b a "default" rule.
"A couple of other examples are Rule 16-2 which 'deems' a ball that is overhanging the hole to be 'at rest' after 10 seconds even if it is still moving," Jones said. "And Rule 27-1c, Ball not found after 5 minutes, 'deems' a ball love after a five-minute search even if it is found and identified by the player at five minutes and one second."
So even without TV cameras and instant replay, you should be able to determine conclusively if you've run afoul of Rule 18-2b and what to do about it.