Decision fatigue shows up in the trade log before it shows up in the mind

[Fairman]

Decision fatigue shows up in the trade log before it shows up in the mind

After a couple of hours of fast decisions, quality drops quietly. Nobody feels foggy, yet the log tells a different story: entries drift a pip or two later than the rules say, stops get nudged, and marginal setups sneak through that would have been skipped at the start of the session.

The best way to catch it is comparing the first hour of trading with the third. Look at win rate, average hold time, and how often the trade matched the written criteria. Many scalpers find a clear decline, usually starting around the 90 minute mark.

Fixes are mundane. Cap the session length. Take a hard break at a fixed interval, away from the screen. Cut the number of decisions by trading fewer pairs and using alerts instead of constant watching.

Another trick is a pre-trade checklist with three or four items. When the brain is tired, a checklist substitutes for judgment.

What does the data say about trade quality as the session wears on?