WEEK 15 — BALL UNPLAYABLE
As we learned in Week 12, in order to apply Rule 26 (Water Hazards), the player must have reasonable evidence that his ball is in a water hazard (including lateral water hazards). The standard for applying Rule 28 (Ball Unplayable) is exactly the opposite – this Rule applies whenever the player's ball in play is not in a water hazard. The player is the sole judge as to whether his ball is unplayable, and may deem the ball unplayable any place except a water hazard.
Once a player has deemed his ball unplayable, he may choose one of three options all under penalty of one stroke:
28a: Play a ball as nearly as possible from where the previous stroke was last played. This is often referred to as "stroke and distance." (See Rule 20-5)
The difference between option a and the other two is that in order to apply Rule 28b or 28c, the player must find and identify his ball. The reference point for applying these two options is the spot where that ball lies. Without knowing this reference point (i.e. without finding and identifying the ball), the player may not proceed under Rule 28b or 28c.
Ball Unplayable in a Bunker
If the player's ball lies in a bunker, he is permitted to deem it unplayable and use any of the options under Rule 28. However, if the player proceeds under Rule 28b or 28c, the ball must be dropped in the bunker.
Reprinted with permission from the USGA.