What actions may be taken to prevent a disturbance to the head by a bowl in course from an adjacent rink?
Any player at the head can choose whether to lift the bowl at rest to allow the other bowl to pass and then replace it as long as this action would not influence the outcome of the head, or stop the bowl from the neighbouring rink. Laws 22.214.171.124 & 126.96.36.199
If a jack at rest on the rink is in danger of being moved by a bowl from a neighbouring rink, any player at the head or the marker must stop the bowl. Law 38.6
During a Club Singles Championship event a bowl from another rink is likely to collide with the jack on the rink on which you are marking. What action should you take?
I would stop a bowl from another rink which is likely to displace the jack on the rink on which I am officiating. If the bowl was on a course that would take it to its own rink I would return it to be replayed. Law 38.6 or 42.2.10