The structured retry

The structured retry. After the autopsy, retry the same task once with one change — not a full redo:

• If reading was slow: retry with the spec pre-underlined (by you, from memory) and compare times.
• If planning was slow: retry writing ONLY the skeleton (comments
  • signatures), then check it against your finished first attempt.
• If coding was slow: retry typing from the skeleton without looking at your first solution; the difference is your fluency gap.
• If testing was slow: retry running your three boundary cases before the example case.

One change per retry, or the measurement is noise. The checkpoint is a 15-minute full class under the same protocol — and its hidden tests are the boundary cases, which is exactly where a rushed submission dies.