Anthropic reports 1785 Elo for Claude Fable 5.2 on AA-Briefcase v1.1 (Elo). In the same table Anthropic shows Opus 5.5 at 1800 Elo.
Tasks: Elo rating; knowledge work.
Setting: Highest-available effort, per the table footnote; the effort level is not named for this row. Numeric reasoning and token budgets are not stated.
Limits: Provider-reported by Anthropic in its launch announcement; not independently reproduced here. Anthropic points to the Fable 5.2 and Mythos 5.2 system card for methods; that card was not opened, so task subset, sample size, harness, prompts, trial counts and run dates are unverified. Results under the same benchmark name can be shown together as reported scores, but unmatched settings and missing methods rule out a controlled ranking. Elo is a relative rating that depends on the comparison pool; it is not a percentage and must not be charted with the rubric score. Anthropic's own table shows Opus 5.5 higher on this measure.
Anthropic
