text: I've followed an advisor who uses a few such strategies going back to the 1980s. All are computer based programs where statistical analysis makes all of the "decisions" and no opinion (otherwise known as overiding the formula-based  investment approach) is allowed.  There have been some, albeit short-lived  disappointing periods over that 20+ years but I accept that will always be the case. But sticking with the purely statistical (zero human input error) approach has provided me with returns that are many times wha the market has returned. 
  Numerous studies show that this is indeed possible or likely. See the Schmidt 1979 - 1993 study as one that produced, on a purely data-driven basis, a 39% per year return for 15 years.........after costs. 
  That study showed these exceptional returns from 1979 - 1993. Anyone who used that study as an investment model since it was published and faithfully with no second guessing, would haves continued to enjoy exceptional returns.