You shouldn't rely on the connection to be good, expect variable delays.
You need some kind of time synchronization, and timestamp certain events so that even when the other side is to late, it can calculate where the ball should be at that moment, and the game stays in sync.
As I understand it, the minimum you should send/timestamp is the pallet position while it hits the ball and/or the outgoing vector of the ball, from then on the other device can calculate on its own what will happen until he hits the ball en does the same. Any pallet updates from then on are supplementary.