A reliable swing is one that is repeatable. A lot of having a repeatable swing starts with set up. You hear pros talk about going through their " routine". They do everything the same way, every time, making sure their alignment, posture, ball position, etc are the same. every time. They take the club back the same way, on the same plane. every time. if they are distracted, they stop and start the whole routine over.. the object is to swing the same way every time, with every club. After countless hours of practice, it finally becomes second nature, and the results of their golf shots are consistent. Almost every time.