QLast week, my ball was on the putting green. As part of my putting routine, I gently place the putter head behind the ball first and then take my stance. For some reason, my ball shifted a few inches. I'm confident I never touched it. Considering that and the fact that I had not fully addressed the ball, am I absolved from penalty? --
Joachim (Myrtle Beach)
AJoachim, you're correct that you did not incur a penalty under Rule 18-2b Ball at Rest Moved by Player After Address because a player has not addressed the ball until he completely takes his stance.
However, Decision 18-2b/4 tells us that if the ball moved after your club was grounded but before you had completed your stance, you would have incurred a penalty stroke under Rule 18-2a Ball at Rest Moved by Player in General. That is, unless there is strong evidence that wind or some other agency caused the ball to move.
Was there such an influence? Please remember that the evidence must be strong. After all, your ball was sitting perfectly still until a club head was placed behind it, right? So, unless there was an earthquake or a sudden gust of wind, it looks like you need to replace the ball and add a penalty stroke.
Some golfers choose to putt without ever grounding their club heads. It lessens the chance of the ball moving. Better luck next time.