Google and AI Source Overlap Across 8 Legal Niches

A descriptive US-English benchmark of the overlap between explicitly exposed ChatGPT and Gemini citation sources and paired Google organic Top 20 results across 8 legal niches. The release contains 288 frozen questions, sector- and niche-level summary estimates, task-level URL and domain overlap metrics, ChatGPT-Gemini domain Jaccard results, top cited and matched domains, the full question and prompt manifest, a data dictionary, checksums, citation files, reusable figures, and an XLSX workbook. Fieldwork: August 7, 2026. Author: Evgeniy Yudin (Rotgar). Methodology reviewed by Boris Teplyakov, SEO Lead. The review covered methodology only and was not a legal subject-matter review of the questions, answers, or cited sources. This study measures descriptive source overlap only; it does not measure answer accuracy, source authority, rankings, traffic, leads, or legal matter outcomes. Canonical study: https://rotgar.com/law-firms/resources/google-top-20-chatgpt-gemini-source-overlap