One idea, one symbol: trading only the cleanest expression

[FXS London Scalper]

Dollar weakness at the London open shows up in EURUSD, GBPUSD, AUDUSD and gold at once. Scalpers often take two or three of them because "the idea is strong". In reality that's one bet with multiplied size and multiplied cost.

A better habit is to pick the single cleanest chart for the idea:

- Clearest structure: a defined level, a clean range break, not a choppy mess.
- Lowest cost relative to expected move. EURUSD with 0.2 spread and a 10-pip expected move beats GBPJPY with 2.0 spread and a 15-pip move.
- Least scheduled news risk in the next hour.

A quick comparison table at the start of the session helps:

Pair | Spread | 15m ATR | Ratio | Level quality
EURUSD | 0.2 | 6 | 30 | clean
GBPUSD | 0.6 | 8 | 13 | messy
XAUUSD | 0.25 ($) | 2.5 ($) | 10 | clean

The ratio column (expected range divided by spread) quickly kills some candidates.

Anyone else run a single-expression rule? How do you handle the days when the "clean" one doesn't trigger but another does?