Making external focus the basis of your golf swing means to transfer the basis of swing movements from the body to the golf club, and from there to the mind. You need to know what you want the club to do and then create a simple, precise, and easily understood image of the club doing just that. Then you use the image to place your unconscious mind in control of the stroke, which directs your body to move the club the way you want it to, automatically.
What we want the club, or more importantly, the clubface to do, is to face the target at the start, move away and back again, and at its return still be facing the target squarely and traveling directly at it. The clubface is the important thing because that is the part that actually strikes the ball. The rest of the club is irrelevant.
You will make a normal golf swing, nothing different there, but you will have an image of something else.
Take the clubface back square and along the ball-target line. As the backswing progresses, imagine in your mind that the clubface as it rises up stays directly over that line and is still aimed square to the target. This will not be so in reality, but imagine that it is, and it will feel like it is.
To get the clubface back to the ball, imagine in your mind you are swinging it along the ball-target line, and the clubface is square to the target, the entire time. Again, this is not reality, but your imagination will make you feel like this is what you are doing.
I know the body cannot move the clubface according to that imagination, but it does not have to. The physical swing does not need to mirror the mental image. The mind and body have different rules and operate in different ways to accomplish the same task.
We all know that feel is not real. You’ve heard that so many times. The physical swing creates a physical feeling that interprets into your mind as … something.
With external focus we do that same thing but in the opposite direction. We start with an image in mind that creates a feeling that is interpreted into your body. The strength of this approach to the problem of swinging a golf club correctly is that it follows an order of events that conforms to how human beings “work.” The mind leads the body.
When we base the swing on a physical movement (internal focus), one swing is seldom the same as the last one, and we can frequently be unsure. But if we have an image of what something outside ourselves is doing (external focus), in this case, the clubface, the image can be identical every time. That leads to much more accurate and consistent physical movement.
All this is not to say, get the right mental image and you’re done. You still need a good grip. You still need good tempo. The handle still leads the clubhead. Etc. Without good technique your mind can’t lead you in the right direction.
In a nutshell, with technique alone, we often swing with the hope that all the separate parts will add up to a well-struck shot. That way works sometimes. The function of the external focus process is to create a unity of technique that produces a swing that works all the time.