Cool. What about a remote the player holds or places on the rail while shooting? When all the balls stop rolling they press a button to stop or reset the clock. When their turn ends they can hand the remote to the incoming player or leave it at the table. There could even be a delay between resets or between players. Some digital chess clocks do this, a delay before the time starts running. What I like even better is not an absolute number of seconds per shot but a bank of time for the whole game for each player, again, just like a chess clock. So maybe you shoot your first shot in 20 seconds but your next shot you take 37 seconds to think about. You will have used 57 seconds out of some total. Your clock keeps running until you miss or foul or your turn ends. Then you press a button and your time stops and your opponents time starts, again with a 5-10 second delay to allow for the transition.
