I think trading skills is not the right word. It is only you can say experienced trading. Who are more experience in doing trading they know everything about trading because experience says all.
There are trading skills to people who knows how to trade,the experience they have in trading have given them the skills on how you can possibly go about trading without loosing. Most people fail because they lack that skill,so if you tell me there is no skill in trading,then I won't agree with you,Every good trader has a way he or she goes about trading without loosing,so skill is involved in trading.