The derivation of the word Duffer, from Golf Illustrated 1901.
“The history of the word ‘duffer’, now a common synonym for any kind of incompetent person, is rather curious. It was, at first, simply another name for a pedlar or hawker. As the country got opened up and shops grew commoner, the packman felt the stress of competition, and gradually became less honest in his dealings. Amongst other things he bought inferior or imitation goods at low prices, and sold them at high figures under the pretence that they were smuggled. To this he added fortune telling and all other kinds of chicanery. In course of time so unprincipled did he become that the ‘duffer’ was only another name for a cheat and swindler. The word is now applied by a process familiar to philologists, to those who are easily cheated or bamboozled and more particularly, as at Golf, to those who betray great ineptitude at whatever they may be engaged.
The word is still a term of opprobrium, but it no longer conveys any suggestion of moral turpitude. It is possible to be a cheat without being a ‘duffer’, and to be a ‘duffer’ without being a cheat. To be both is surely the lowest depth of degradation.”