In the article I read the following:

Despite common perceptions to the contrary, it is actually quite straightforward to locate profitable trading strategies in the public domain. Never have trading ideas been more readily available than they are today.

What is the input of the "retail" trader then? Especially considering that at this level tech does not make a difference (all have access to somehow high computing power).

By the way, any good backtesting tool in python or R? I started implementing a simple trading algo last week during my freetime (yeah, I have to go out more) and I was wondering how will I test it.