A strategy wins 70% of the time. Another wins only 40%. Which one is better?
The obvious answer is the 70% strategy. It is also often the wrong answer. Win rate tells you how often you win, not how much you make when you win or lose when you are wrong.
A trading system should be judged by the combination of win probability and average payoff. Expected value can be written as: Win Rate × Average Win − Loss Rate × Average Loss. A high win rate can still produce negative expectancy if losses are much larger than gains.
The Win-Rate Trap
Imagine Strategy A wins 7 trades out of 10. Each winner makes $100, but each loser costs $300.
Seven wins make $700. Three losses cost $900. After ten trades, the strategy is down $200 even though it was “right” 70% of the time.
What Is the Risk-Reward Ratio?
Risk-reward compares what you are prepared to lose with what you realistically expect to gain. If you risk $100 to target $200, the reward-to-risk ratio is 2:1.
A larger payoff relative to the loss means you can be wrong more often and still potentially maintain positive expectancy. But a beautiful 3:1 target is useless if the market almost never reaches it. The assumptions must come from actual results, not wishful chart drawing.
| Win rate | Average win | Average loss | Expectancy |
|---|---|---|---|
| 70% | $100 | $300 | −$20 |
| 50% | $150 | $100 | +$25 |
| 40% | $250 | $100 | +$40 |
| 30% | $300 | $150 | −$15 |
These are simplified examples before fees, slippage, taxes, and changing market conditions.
Your Risk-Reward Ratio Implies a Break-Even Win Rate
If your average win equals your average loss, you need to win more than half the time before costs. If your average winner is twice your average loser, the mathematical break-even win rate falls to roughly one-third before costs.
This is why asking “what win rate should a good trader have?” without knowing payoff size is almost meaningless.
A strategy that looks slightly positive before commissions, spread, slippage, taxes, and financing costs can become negative after execution. Paper calculations should use realistic net outcomes whenever possible.
Why Ten Trades Are Not Enough to Declare Victory
Expectancy is a long-run concept. A positive-expectancy strategy can still suffer several losses in a row, and a negative-expectancy strategy can enjoy a lucky winning streak.
That means you need a meaningful sample of comparable trades and consistent rules. If you change the setup, stop, target, and position size every few trades, your “win rate” may be a pile of unrelated numbers rather than useful evidence.
- 1Record wins and losses using net results after trading costs.
- 2Calculate average win and average loss, not only the largest examples.
- 3Compute expectancy for a meaningful sample of comparable setups.
- 4Track whether the numbers change across market regimes.
- 5Use expectancy as evidence, not as a guarantee that the next trade will win.
Frequently Asked Questions
What is a good win rate in trading?
There is no universal good win rate. A 40% strategy can be profitable if winners are sufficiently larger than losers, while a 70% strategy can lose money if losses are too large.
Is a 2:1 reward-to-risk ratio automatically good?
No. It only becomes useful when paired with an achievable win rate and realistic execution. A target that is rarely reached can produce poor expectancy despite an attractive ratio on paper.
Does positive expectancy guarantee profit?
No. Expectancy describes the average result you would expect over many comparable decisions under the assumptions used. Real outcomes vary, market conditions change, and estimation error matters.
