How Measure My Edge measures a trading edge

By Cltay, founder · Updated 2026-10-31

A trading edge is a positive average result per trade that holds up across enough trades to rule out luck. Measure My Edge measures it in R (multiples of the amount you risked), calculates a 90% confidence interval around your average, and only calls an edge validated after 100+ closed trades with the whole interval above zero. Below 20 trades it gives no verdict at all.

1. What counts as evidence

Only closed trades with a recorded R-multiple count: wins, losses and break-evens. Open trades and trades without a result are ignored. A trade counts as break-even when its result is within ±0.1R, which leaves room for spread and fees.

Results are measured in R, not money, so trades of different sizes compare fairly: a trade that made twice what you risked is +2R, and a full stop-out is −1R.

2. Expectancy: the number that matters

Expectancy is your average R per trade: the total R of all closed trades divided by the number of trades. It combines how often you win with how much you win and lose, which is why it’s the basis of the verdict. Win rate and profit factor are shown too, but a high win rate with small winners and large losers can still lose money.

3. The confidence interval

A good average over a few trades can be luck. To account for that, Measure My Edge calculates a 90% confidence interval around your expectancy: the average, plus and minus a margin that shrinks as you log more trades and grows when your results are more spread out. (Technically: mean R ± t × standard deviation ÷ √n, using the t-distribution.)

If the lower end of that interval is above zero, your results are unlikely to come from a strategy with no edge. If the interval still includes zero, the honest answer is “not proven yet”, however good the average looks.

4. The sample-size gates

The same gate applies to every breakdown. A pair, session or setup needs 20+ trades of its own before its numbers are treated as readable.

5. A worked example

Take one strategy that wins 45% of the time, with winners at +2R and losers at −1R. Its expectancy is +0.35R per trade. Here is what Measure My Edge reports at two sample sizes. (Illustrative numbers, computed with the same engine the app uses.)

The average is identical. At 40 trades the interval still reaches below zero, so the result could be luck. At 100 trades the whole interval is above zero, which is what “validated” means. Try it with your own numbers in the free expectancy calculator.

6. Edge Diagnosis: why results are what they are

Once you have 20+ closed trades, the Edge Diagnosis looks at four things:

• Strategy quality — expectancy on the trades where you followed your own rules.
• Execution discipline — the gap between trades where you followed your rules and trades where you didn’t. It needs 10+ trades on each side.
• Risk consistency — whether some losses are much bigger than your usual loss.
• Evidence confidence — how much the other three can be trusted. It reads Tentative until you have 50+ trades and a confidence interval above zero, then Solid.

If more than one thing needs work, the diagnosis names the most basic one first: strategy, then execution, then risk. There’s no point fixing discipline on a strategy that has no edge.

7. Rule changes don’t mix

Every setup has a version. Changing its rules starts a new version (renaming it doesn’t), and each trade records the version it was taken under, so results from old and new rules aren’t blended into one number.

8. What the AI does — and what it can’t do

The AI Scanner reads a chart screenshot and checks it against the setups you defined, returning “valid”, “wait” or “no trade” with the rules it found met or missing. It doesn’t predict the market, and “no setup qualifies” is a normal answer.

The AI can’t reliably read exact prices from pixels. It proposes entry, stop and target levels, and you confirm or correct every price before anything is used to size a position. The edge statistics come only from the outcomes you record, never from the AI’s opinion of a trade.

9. Limits

Statistics describe your past trades; they don’t guarantee future results. A validated edge can fade when market conditions change, and the numbers are only as accurate as the trades you record. Trading carries risk of loss. See the Terms & Disclaimer.