except for HFT trading I think a good discretionary trader can easily outbeat most of computers out there. Learn price action, though that might take you a couple of years to get any good at it (count no less than three). And that's if if you are willing to put hard work into it and spend like 10 hours a day in front of your screen, not looking but actively watching in a focused way.
garbage in garbage out, most computers programs just suck, just look at the returns of most hf's ... no computers are not good at trading ...
Did you ever play World of Warcraft? In a video game the monsters are far inferior to the human controlled players. In real markets you fight against real people. You take real people's money when you win. You lose your own money when you make a bad trade. You don't get a second chance at a trade.