Risk management is not just how to reduce losses, but also how to balance risks and rewards. This article explains how the profit-loss ratio and winning rate mutually restrict each other, how expected value puts a single result into a long-term perspective, why positions should be adjusted according to the risk-reward structure and exit conditions, and why there is no clear stop-loss and take-profit, and the profit-loss ratio is only a number for retrospective review, and why the sample size and time span determine whether the judgment is valid, helping traders use probabilistic thinking to replace the emotional response to a single profit or loss.