The "best/good" signals from indicators are not random at all.
Problem is that your indicator, which has been designed for certain market conditions, wont work consistently in all market conditions.
Simplest one I can think of is a moving average - only buy when price is above 200MA. Works great in a trend but get stuck in a range and you get carved up. And its no good saying that its a successful indicator when used with common sense because then whats the point of having the indicator in the 1st place? May as well remove the indi and use common sense
