Ball on the Green?
Question: - When a ball is on the edge of the green is it classified as on or off the green?
Answer: A ball is on the green when any part of it touches the green.
(R&A Rule’s definition Putting Green)
A ball on the putting may be lifted, cleaned and replaced, without penalty, (unless it is on the wrong green)
A ball on the wrong green must be lifted and dropped without penalty at the Nearest Point of Relief. (Rule 25-3b)