The White Elephant story is right out of H.A. Dorfman's "The Mental Game of Baseball."
I begin by telling the kids that I'm going to tell them a story about a White Elephant, but while I tell them this story they can't think about the White Elephant. They CAN'T picture a White Elephant, I DON'T want them to see a White Elephant. Now right after I tell them not to, I ask if any of them thought about it. Most of them say yes they did.
The moral of this is that your mind doesn't picture NO, DON'T, CAN'T. So when you tell yourself, "DON'T throw a ball" or "I CAN'T strike out here" or "I hope I DON'T throw the ball away", your mind only pictures the action happening, it doesn't picture not doing the action.
So instead of saying to yourself, "Don't throw a ball" we want them saying "Throw a strike." These are the exact same goals, but our mind interprets them differently.
I can't strike out = I'm going to make contact
I hope I don't throw the ball away = I'm going to make an accurate throw
This is all positive self-talk vs negative self talk. Also, it can and should be utilized in goal setting.