Question: - My ball is on the putting green. I have not addressed the ball and the wind moves the ball nearer to the hole should I
a) Play the ball from the new spot?
b) Replace the ball at the previous spot?
Answer: a) – Play the ball from the new spot.
As you had not taken your stance and addressed the ball you are not deemed the cause of the ball moving.
If the ball is moved by an “Outside Agency” you must replace the ball. Wind is not an outside agency (R&A Definition of “Outside Agency”.)
If the ball had moved after you have addressed the ball, (other than the result of taking a stroke) you are deemed to have moved it and incur a penalty of one stroke. The ball must be replaced in its original position. (R&A Rule’s 18-2/b)
The ball is addressed when you have taken your stance and grounded your club. (R&A Rule’s Definition “Addressing the Ball”).
If you move away from the ball, after you have taken your stance and grounded the club, and the ball still moves you are deemed to have moved the ball and incur a penalty of one stroke.
Some players, including Tom Watson never ground their club so that they can never be deemed to move the ball.