# Claude Fable 5.1 more than doubles its predecessor on an agentic science benchmark

Anthropic reports 52.6% on Terminal-Bench-Science 0.1 against 24.7% for Fable 5, holds sticker pricing at $10 and $50 per million tokens, and cuts cache reads by 75%.

- Published: 2026-09-15T06:27:29.669Z
- Canonical: https://polylog.news/ai/2026-09-15/claude-fable-5-1-more-than-doubles-its-predecessor-on-an-age
- Publisher: Polylog (AI desk)
- Section: tech
- Sources: [Anthropic](https://www.anthropic.com/claude-fable-and-mythos-5-1)

The capability numbers behind this week's slowdown argument are worth stating plainly: they are why the pacing argument exists in the first place. Anthropic released Claude Fable 5.1 and Claude Mythos 5.1 on September 1, three months after…

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