Definitions first.
Static balance is when you have a place where the ball will naturally rest (e.g. the palm of your hand), and you don’t need to do anything to keep it there. Dynamic balance is when you need do constantly adjust to keep the ball where you want it, for example on the top of your head (not on a flat spot, or indentation).
I’ve been working on rolling to the static spot on my outer elbow, and I’ve gotten reasonably (50%) good at it. But one side effect is I’ve gotten MUCH better at dynamic balance on my arms. If I miss the spot on my elbow by an inch or two, I can roll it back to where I want it to go.
I’ve also gotten much better at just rolling the ball up to my shoulder, and back to my hand, even though I haven’t been practicing that.
