Background
During a discussion about investment systems, someone asked: Does a high win rate mean the system is good? This dialogue starts from the essence of win rate and gradually explores its true position in a system.
Key Concepts
- Scope of this series: Trend investing — not short-term trading or value investing
- Win Rate: The proportion of correct judgments, which doesn’t describe the cost of being wrong
- Positive Expectancy: The statistical property where long-term gains exceed losses
- Risk-Reward Ratio: The ratio between single-trade gains and single-trade risks
1. Does a High Win Rate Mean the System Is Good?
Q: Does a high win rate mean the system is good?
Response: Win rate only describes the proportion of correct judgments. It doesn’t describe the cost of being wrong.
2. What’s More Important Than Win Rate?
Q: What’s more important than win rate?
Response: The ratio between single-trade gains and single-trade risks, and their distribution over the long term.
3. Can a Low Win Rate System Still Be Profitable?
Q: Can a low win rate system still be profitable in the long term?
Response: Yes, as long as the gains when correct are enough to cover multiple mistakes.
4. How to Improve Long-Term Win Rate?
Q: How does a system improve its long-term win rate?
Response: Not by improving judgment accuracy, but by filtering out trading environments that clearly lack an edge.
5. The True Position of Win Rate in a System
Q: So what is the true position of win rate in a system?
Response: It’s a result statistic, not a design objective.