Writing Craft

Most writing skills are someone's opinion about good writing.
These nine came out of a blind test of 50 samples, scored by 3 AI judges who had no idea who wrote what. Then they were measured in a second blind test.

Works in Claude Code, Codex, Gemini, or pasted into any chat.
The skill itself is two files: SKILL.md and check.py.

Install · The nine rules · Does it work · Where they came from

▶  Watch the blind test on YouTube

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Five models were given the same five everyday writing jobs, twice each. 50 outputs. Filenames scrambled, punctuation stripped, the answer key locked until every score was in. Three judges then scored all fifty blind and were each asked one open question, in their own words, with no vocabulary supplied: **what separated the high scorers from the low ones?**

Nine signals came back. All three judges named the first four independently, without seeing each other's answers.

The skill turns those nine signals into rules the model writes to. **Load it, ask for the copy you wanted anyway, and the draft comes back better.** The model writes to the nine, checks its own work against the three that are measurable, fixes what missed, and only then hands it to you.

You don't run anything. You don't paste a draft in for marking. You ask for a post and get a better post.

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Does it actually work

The same blind test was run on the skill itself. Sonnet 5 with it and without it, judged in one sitting by GPT-5.6 Sol, same five prompts, twice each.