"I've seen tons of indicators/systems that look good on a variety of charts but fail to be profitable on long-term tests." Sounds like I need an indicator that is self adjusting to trending or range bound conditions. Thanks !I'll get on that immediately.
Look at the work of John Ehlers. Specifically, his method of determining the dominant cycle, and his Inverse Fisher Transform RSI indicator. His method(s) of determining trend mode or cycle mode may help you as well.
EVERYTHING is predictive, unless you are trading to lose money. Whether you use Price Action or TA, you take your signals based on something. In Price action it can be a breakout of a triangle, 3rd/4th bounce on a trendline, 61.8% retracement, or fundamental news, in TA when two moving averages cross, RSI hits zero or the planets allign. If what we do generally after deep amount of backtesting, in my case min of 3,000 sample size and ten years using tick data, we all make our judgements based on one or combination of rules. And unless you have backtested a great deal, what you think you see might only work for past six months cause of more/less volitility, government changes to economy, weather changes, explosions dealing with energy, governements turmoil. I once did 23 losing trades in a row, now if I had quit based on method not being very predictive in winning percentages, I would have missed the Coffee trade that made 2.5 times of what I lost on the 23 losses. The getting in is easy, after that is where the money comes.