Over the past 15 years, research on focus of attention has consistently demonstrated that an external focus (i.e., on the movement effect) enhances motor performance and learning relative to an internal focus (i.e., on body movements). - Gabriele Wulf
Recently I had a discussion with a friend, golf movement analyst, about the role of focus in swing consistency development. There are opinions that one needs to practice all the swing positions and sequence, and that alone will bring precision and consistency at impact.
In other words, by using Internal focus and perfecting the procedure, consistent transition from one leg to another, position of various body parts and the club, one will automatically achieve perfect ball contact precision.
In such a way one can program a machine, a robot like Iron Byron, but not a human. In one way a person can't do what a robot can do and, on the other hand, a human can do what no robot can do. Although it can be said that humans' body and the brain is also a kind of machine, they are different.
You work on all the swing and body positions, but you do not work on direct sweet spot precision. In this way, you can become well trained with all the body positions, but there is little chance that you will automatically become precise at ball contact. A few millimeters of inconsistency at this most important place is enough for bad and inconsistent shots.
It does not take a lot of time to learn basic golf swing technique. Of course one then needs a little more time than what was learned becomes natural and one can swing without tension, fluid and fast. This can/should be done without considering hitting precision or even without a ball, with dry swings.
After this basic swing shape becomes natural, one can start with the real practice, the skill practice. The skill of hitting the ball with the sweet spot. Or, as Moe Norman said, "Put this dumb guy on that dumb guy..."
When you deliberately concentrate directly on trying to hit the ball with the sweet spot, you trigger corresponding neurons that are responsible for this thoughts, feelings, and activity.
This feeling of a good sweet spot hit should be at this point the primary focus of attention, namely that the pathways between neurons that fire in relation to that feel get myelinated.
When you do this all the other aspects of the swing get trained automatically because the body repeatedly does the same thing to assist good sweet spot hit. The body automatically does everything it can to assist the goal, the precise sweet spot hit, so one should allow finer changes to his swing the body wants to do.
In one of his interviews, a tour pro Padraig Harrington said that when he visualizes and targets different shots, all the swing changes happen automatically.
So the main point I see is that when trying to improve impact location precision, the process works successfully when you directly concentrate on hitting the ball precisely. It does not work vice-versa, namely, that impact precision will automatically improve if you work/focus separately on the other aspects of the swing, like transfer of the body weight, back swing, down swing, etc.
Let's say you focus internally on your shoulder turn during your swing. The neurons in relation to shoulder turn focus, movement and sensation fire more powerfully then neurons in relation to other aspects of the swing. After practice, the shoulder turn becomes successfully trained, but not precise impact location.
Here is a picture of correct alignment:
The truck, the most powerful and leading "neuron" is in front. In this way, he is powerfully pulling all other cisterns that automatically follow and the whole execution of the task goes very smoothly. All focus is in the truck, here is the engine, here is the steering mechanism and the driver that controls the whole procession.
Now let's say that you put one or two cisterns before the truck so that the truck is somewhere in the middle of the procession. Needless to say, it will be a disaster because the cisterns, being without control, in front of the truck, will go their own way off the road.
Top players say that they feel the impact and see the flight of the ball before even starting the swing. As soon as they visualize the shot and the ball flight, they feel the push in their bodies to execute the swing. So neurons in relation to this feel and visualization fire powerfully and they automatically drag all the others neurons in relation to the swing execution just as the truck powerfully drags the cisterns.
The best way the truck and cisterns go is when there is no interference with the cisterns. If you would put another engine or steering mechanism to one of the cisterns, it would not go as smooth as when the truck is the only one with the steering mechanism and the engine, and all the cisterns just follow.
So if you want to make a certain impact and ball flight, you should allow that feel of impact and ball flight vision make changes to your swing they want.
This is in accordance with Harrington's statement, how all the changes in his swing happen automatically according to his ball flight visualization.
Of course, optimal focus varies with the skill level. A beginner, when he learns the basic technique, will focus Internally, means on the movement of bodily parts. After the basic swing movement starts becoming natural, now its time to gradually switch to different levels of External focuses.