Redundant mooring lines

For an overnight mooring on a monohull, I was taught that it's a good idea to pass two bow lines through the mooring eye. One line goes from the starboard bow cleat through the mooring eye and back to the same cleat. The second line does the same thing on the port side. The advantage of going back to the same cleat is that chafing at the eye is minimized. The advantage of two lines is redundancy.