So, what's new?
In 2019, if a player's ball at rest might have moved, new Rule 9.2 will introduce the "known or virtually certain" standard. This means that something is at least 95% likely and it will apply to all questions of fact when deciding:
whether a ball at rest has moved, and
what caused a ball at rest to move
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.
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