How can you throw a ball as hard as you can and have it come back to you even if it doesnt hit anything there is nothing attached to it and no one else catches or throws it?

Answer 1

Throw the ball straight up in the air.

or

Throw the ball against the wind.

Answer 2

This is obviously not a Baseball question, but I'll humor you anyway. If you throw the ball straight up, gravity will pull it back down to you.