How short is too short
Caleb's solution for the ball sounds good.
What kind of bow do you have? If you cinch the mooring ball right right up tight, will it stay off the hull? That will not work with a plumb bow.
Second page has a picture of the boat at the mooring.
It it not dead plumb but close.
In my case I have no automatic way to cinch the ball as it is free to slide up and down the chain.