I spent a month doing something slightly unhinged: I pulled 400 above-average LinkedIn posts across 10 verticals, ran them through a fleet of analysis agents, and reverse-engineered why their first lines worked. Then I turned the findings into open-source skills for Claude Code and Codex.
This post covers what the data said, what surprised me when I pressure-tested the skills, and where to get them.
The dataset
400 posts that outperformed their authors' baselines, spread across 10 verticals: founders, marketing, engineering, sales, HR, finance, design, data, product, and personal brands. For each post I tracked the hook (first 210 characters, everything before "... see more"), the structure, the engagement split (comments vs reposts vs likes vs saves), and the author's baseline so a big account's average day did not read as a small account's viral hit.
The single strongest signal was boring and consistent: the hook does most of the work, and hooks are formulaic. Not "formulaic" as an insult. The same 16 first-line patterns kept producing the outliers, vertical after vertical.
