Originally Posted by Rex Hudler
Just to expand on what you said...... basically, players develop muscle memory over the years. In a nutshell, a swing has to be crafted so that once a hitter decides to swing, then he does so immediately without any thought. A hitter has about three-tenths of one second to decide whether to swing, where to swing and at what speed the ball is coming at him. The swing itself once started is finished by simple muscle memory. Its similar to many things we do daily that we never thing about, just because we have trained our body to do them. They become 2nd nature.
To change that is easier for some than others. That is where the mental aspect comes in. That doesn't mean someone that can't change as easily as another is dumb. People are "wired" differently. I used to teach hitting lessons to kids and some kids can pick up on changes you make or on trying to do something new almost immediately. Others struggle and seem stiff while trying to change what they have always done. It is less exaggerated but similar at a professional level.
Once you try to make a change, until it becomes second nature, you are thinking about it. The one thing that is true in the batters box is there is no time to think about the mechanics of your swing. If that is in the back of your mind at all, then it will slow down the process, often making the swing longer or awkward, especially on breaking balls.
Good stuff. On a much lesser scale, think of trying to change your swing like trying to change which finger you use to type certain keys when you are typing. It seems like a very simple thing to do, but if you have been typing your entire life one way, changing it is very difficult, and you will be thinking about it every time you try and hit that key/key combo (Shift+" ") You will be typing much slower and meticulously for a while until you get the hang of it.
Once you get used to it you may still end up reverting back to the old form if you don't keep tabs on yourself and make sure you are doing it the "new way".
I know the analogy doesn't fit really good, but it's the best, down to earth analogy I could come up with.