I know that Technical Analysis works in the sense that it can give reasonably reliable indications that a stock is more likely to move up than down (or vice versa). In other words, systems with relatively high win loss ratio

This is distinct from TA approaches that rely more heavily on stop-loss/money management aspects to make a system profitable. In other words, systems with a lower win-loss ratio

So my question is, why/how does TA reveal opportunities that have a relatively high probability of producing a profit?