RankingAA-Briefcase

AA-Briefcase

Data updated 12 Sept 2026

Bucket
Supporting evidence
Unit
elo
Direction
Higher is better
Version
Display harness
Claude Fable 5.1 and Claude Mythos 5.1 System Card
Board
https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card

The available records have no admitted matched comparison in the capability core. Raw results remain available below.

Compare published benchmark results with category weights →

Models

ModelScoreHarnessEvidenceSource-recorded date
Claude Fable 5.1Anthropic1694
Reported settings & source

Artificial Analysis long-horizon knowledge projects; rubric and panel pairwise judging; Claude max effort.

Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures.

Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.1.A;8.15.4 · reviewed 2026-09-12

Claude Fable 5.1 and Claude Mythos 5.1 System Cardlab self-report2026-09-12
Claude Opus 5Anthropic1685
Reported settings & source

Artificial Analysis long-horizon knowledge projects; rubric and panel pairwise judging; Claude max effort.

Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.1.A;8.15.4 · reviewed 2026-09-12

Claude Fable 5.1 and Claude Mythos 5.1 System Cardlab self-report2026-09-12
Claude Fable 5Anthropic1572
Reported settings & source

Artificial Analysis long-horizon knowledge projects; rubric and panel pairwise judging; Claude max effort.

Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures.

Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.1.A;8.15.4 · reviewed 2026-09-12

Claude Fable 5.1 and Claude Mythos 5.1 System Cardlab self-report2026-09-12
GPT-5.6 SolOpenAI1502
Reported settings & source

Artificial Analysis long-horizon knowledge projects; rubric and panel pairwise judging; Claude max effort.

Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.1.A;8.15.4 · reviewed 2026-09-12

Claude Fable 5.1 and Claude Mythos 5.1 System Cardlab self-report2026-09-12
Claude Fable 5.1Anthropic1686
Reported settings & source

Artificial Analysis; xhigh effort.

Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures.

Claude Fable 5.1 and Claude Mythos 5.1 System Card · 8.15.4 · reviewed 2026-09-12

Claude Fable 5.1 and Claude Mythos 5.1 System Cardlab self-report2026-09-12
Claude Fable 5.1Anthropic1611
Reported settings & source

Artificial Analysis; high effort.

Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures.

Claude Fable 5.1 and Claude Mythos 5.1 System Card · 8.15.4 · reviewed 2026-09-12

Claude Fable 5.1 and Claude Mythos 5.1 System Cardlab self-report2026-09-12