What counts as a valid M1 impulse candle in my rules

[FXS London Scalper]

"Wait for an impulse candle" appears in a lot of scalping advice. Without a definition it means whatever your mood says it means. Here is mine for EURUSD and GBPUSD on M1.

A candle qualifies only if all four are true:

1. Range is at least 1.8 times the average range of the previous 20 candles.
2. Body is at least 70% of the full range. Long wicks mean disagreement, not impulse.
3. It closes beyond a level I had marked before the move: Asian high/low, prior hour extreme, or a round number.
4. Spread at the close of that candle is no more than 1.5 times my normal for the hour.

If it passes, I don't chase. I wait for the first pullback that holds inside the upper (or lower) half of that candle.

Why so strict? Because when I tracked loose "impulses" for two months, about half of them were news spikes or stop runs that reversed immediately. With the four rules I take maybe 40% fewer trades, and the hit rate improved enough to more than cover that.

Not saying these numbers are right for everyone. My point is that you need numbers at all. What does your definition look like?