It doesn’t happen too often on the golf course, but golf balls do occasionally collide. If you’ve played a shot from off the putting surface and your ball hits another ball, what to do is covered by Rule 11.1 – Ball in motion accidentally hits person or outside influence…
First of all, there’s no penalty and the player whose ball was in motion should be played from where it has come to rest.
For the player whose ball has been moved, they should follow Rule 9.6 – Ball lifted or moved by an outside influence.
But what about if your ball knocked another player’s ball into the hole?
As long as your shot has been played from off the putting surface, the Rules above apply – You will play the ball as it lies and the person whose ball has been knocked into the cup must replace their ball on its original spot.
If you didn’t play your ball from where it had come to rest after knocking another golfer’s ball into the hole, you would receive a general penalty for playing from a wrong place – Rule 14.7.
If the player whose ball had been knocked into the cup didn’t replace their ball, they would also receive the general penalty.
If your ball (played from off the green) struck another ball at rest and went into the cup, it would be deemed to have been holed as per Louis Oosthuizen’s ace on the 16th hole in the 2016 Masters. His tee shot struck JB Holmes’ ball and was deflected into the hole. The South African’s hole in one stood and Holmes had to replace his ball.
On the putting green
Things are a little different if you have played from the putting green and knocked a ball into the cup.
In strokeplay, if your ball is on the green and it strikes another ball on the putting green (whether it knocks it into the cup or not,) you receive the general penalty of two shots. The player whose ball was struck should replace their ball on its original spot.
There’s no penalty in match play for striking a ball on the putting green with a shot from the putting green but the struck ball should be replaced.
