When ball is out of bounds

Your ball at rest is out of bounds only when all of it is outside the boundary edge of the course.

規則18.2a之圖解: 何時球在界外

一球唯有它全部是在比賽場地的界限之邊界外時，才是在界外。本圖是提供了球何時在界內及界外的示例。

Related Rule - 18.2a(2)