Record the expected pair
When an inserted character differs from the target, the game records the expected character and its adjacent expected two-character pair where one exists. The pair is based on the target text, not a guessed keyboard diagnosis.
A repeated mistake can therefore point to a useful practice fragment, but it cannot establish why it happened. Layout, posture, distraction, familiarity and input behavior are outside this simple record.
Practice in word context
The drill takes up to six frequently missed pairs and finds words in the original passage containing them. Those words form a repeated local practice passage. A pair without a word match can appear directly as a short fragment.
The drill is intentionally different from the original race. Its separate passage fingerprint prevents it from being imported as if it were an equivalent daily challenge. Practice it, then return to the original passage for a comparable run.
Keep improvement claims modest
The mistake CSV and replay JSON show what happened in this session. They do not establish a guaranteed improvement rate, professional qualification or universal ranking.
Choose a comfortable repeatable setup and inspect more than one run. Use the records to decide what to practice next, while keeping the scoring formulas and task difficulty consistent.