Why a 2:1 R:R ratio means nothing without a win rate.
Trading-education content fixates on R:R ratios. Without a paired win-rate estimate, the ratio carries no information about expectancy. The two together do.
The expectancy formula
Expectancy is the long-run average outcome of a strategy, expressed in “R” units (multiples of the per-trade risk):
expectancy = (win_rate × avg_win) − (loss_rate × avg_loss)
For a strategy with 50 % win rate and a 2:1 R:R (avg_win = 2R, avg_loss = 1R): expectancy = 0.5 × 2 − 0.5 × 1 = +0.5R. That is, on average, every trade returns half of the per-trade dollar risk in positive expected value. Over 100 trades at $500 risk each, expected gross profit is $25,000.
The lookup table
Expectancy in R units for combinations of win rate and R:R ratio. Positive entries are profitable; negative entries lose money.
| Win rate | 1:1 R:R | 1.5:1 R:R | 2:1 R:R | 3:1 R:R | 5:1 R:R |
|---|---|---|---|---|---|
| 20% | −0.6 | −0.5 | −0.4 | −0.2 | +0.2 |
| 30% | −0.4 | −0.25 | −0.1 | +0.2 | +0.8 |
| 40% | −0.2 | +0.0 | +0.2 | +0.6 | +1.4 |
| 50% | +0.0 | +0.25 | +0.5 | +1.0 | +2.0 |
| 60% | +0.2 | +0.5 | +0.8 | +1.4 | +2.6 |
| 70% | +0.4 | +0.75 | +1.1 | +1.8 | +3.2 |
| 80% | +0.6 | +1.0 | +1.4 | +2.2 | +3.8 |
Two ways to be profitable
- High win rate, low R:R. 70 % wins at 1:1. Common in mean-reversion, range-trading, and short-term momentum strategies. Psychologically easier (most trades are winners) but vulnerable to a single fat-tail loss event.
- Low win rate, high R:R. 30 % wins at 3:1+. Common in trend-following and breakout strategies. Psychologically harder (most trades are losers) but more robust to fat-tail events because the winners are large.
Both can be profitable. Both can be unprofitable. The strategy's expectancy is the only thing that matters for long-run outcome — not the headline R:R.
Why R:R alone is misleading
0.25 × 2 − 0.75 × 1 = −0.25R — net loss of a quarter of the per-trade risk on every trade. The 2:1 ratio is necessary but not sufficient.
The right discipline is conditional: take trades whose specific R:R, given the specific setup's historical win rate, produces positive expectancy. This requires either tracking your own historical win rate per setup type or using published win rates from rigorous backtests (with a generous haircut for the inevitable backtest-to-live degradation).
The realised-vs-target gap
Target R:R is what you set when entering. Realised R:R is what actually happens, factoring in: stops hit before the target, trailing stops that take you out before the target, gap moves through the stop or target, partial fills, slippage. Realised R:R is consistently lower than target R:R for most retail strategies — typically 60–80 % of the headline figure. Plan with realised in mind:
- If your target R:R is 3:1, plan for realised ~2–2.4:1.
- Win rates similarly degrade in live trading vs. backtest by 5–15 percentage points.
- Combined effect: a strategy that backtests at 50 % win and 2:1 R:R typically lives at 40 % win and 1.5:1 R:R, dropping expectancy from +0.5R to +0.10R.
What the calculator displays
The main calculator reports the R:R as the ratio of reward (target − entry) × shares to risk amount. The figure is the target R:R, not the realised. For realised R:R analysis, you need a trade journal and at least 50–100 closed trades.