Keeping Promises - Calling One’s Shots

“Eight ball in the corner pocket.”
“I’ll call you right back.”
What would our predictions or promises amount to if there were NO regularities in the world? Would there then even be such thing as predictions or promises? Suppose the cue ball does something different each time you strike it. You wouldn’t be able to call your shot. You wouldn’t be able to choose the ball’s course.
Freewill, choosing, promising, are unworkable without some form of determinism. Is the reverse also the case? I don’t know and at the moment don’t care. I think this is enough to show that determinism and freewill can be seen as complementary, that they are not always and only contraries or mutually exclusive.