Successful-short-strategy-on-end-of-day-basis

Hello,

I am trying to develop a short strategy on an end-of-day basis. So, I want to put orders only when the stock exchange is closed and want to buy and sell only on the opening of the market.

Does anybody know, if this is feasible. Some say, it is extremely difficult to create a successful Short-Strategy?

Thanks for your help,
Werner