# @timfduffy — 2026-10-07

♥25 ↻0 · https://x.com/timfduffy/status/2107975984804753609

I'll certainly trust the Epoch ECI result more when it's out, though it won't be directly comparable to Mythos Preview since Epoch did not have access to Project Glasswing. But I think AECI seems trustworthy. For example from Fable 5 to Sonnet 5.5, AECI went up ~4 points while EECI went up ~3.

tags: author:timfduffy, kind:tweet, model:fable, model:mythos, on:claude-sonnet-5-5, year:2026
cited on: _dossiers/claude-sonnet-5-5.md, claude-sonnet-5-5