The standard way to tie up is to run a dock line from each cleat to the mooring pennant. This leaves about 20 to 30 feet of line from the boat to the ball. The ball is free to run up under the bridgedeck and bang the hulls all night long. If you look closely at the pic the mooring pennant is tied directly to the starboard cleat and the length adjusted such that the ball cant reach the port hull. A dock line is added to the ball from the port cleat and adjusted so the ball cant reach the starboard hull. The ball is now trapped and can’t touch either hull or go under the bridgedeck. Swinging radius is also cut way down.