A mistake journal should connect a concrete position with a reusable lesson. It is more useful than a growing list of rating frustrations.
What to do
Save the position, your thought process and the overlooked reply. Classify the cause narrowly, such as missing a loose piece or misjudging a pawn ending. Revisit the position without its answer.
A mistake to avoid
Do not label every loss lack of concentration. That explanation is too broad to guide a specific training change.
A detail worth checking
Keep entries small enough to revisit. One position, one missed idea and one test question are easier to use than a full unstructured game dump that never turns into a practice task.
Try this practical check
Review five entries and look for one repeated cause. Build the next practice session around that cause, then check whether the same error appears in later games.
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