If you choose your own actions where does fate come in?

Ahh! The classic "Choice and Destiny". I posted that once. If we would try to debate this idea, it would be endless. I found another subject to pull my brains out which is related to this, how about, "Cause and Effect". Example, put a ball in a slope going down wards. It's your choice to put the ball there, it's destiny is locked up for falling, unless you catch it, making it your choice. Therefore what caused it to fall is that you put it on top of a slope, so its effect is that it will fall. Kind-a like that. I know you get it.