Model Scorecard
Claude Fable 5.1 (max effort)
Anthropic · proprietary
Claude Fable 5.1 ranks #2 of 82 models on the October 2026 ToneBench board, and Claude Fable 5.1 (max effort) is its best configuration, #3 of 135 configurations, with a Writing Score of 84.5/100 and a Writing Elo of 2543. One script costs $3.56 at API list price.
Last updated , from board data generated at 16:17 UTC.
Rank, scores, the nine metrics, the 10 reference scripts, cost and setup for one configuration (a model at one reasoning setting). Key Results sums it up; the section links below it jump to the detail.
Key Results
- StandingClaude Fable 5.1 ranks #2 of 82 models, and this is its best configuration. As a configuration, it is #3 of 135 configurations by Writing Elo (2543), near the top of the board. Its 95% range (2497 to 2581) overlaps 4 other configurations, ranked #4 to #7, so its exact place among them is not settled.
- MetricsBest-ranked: Tone & Voice Match (81.8, 3rd of 135 configurations, +8.4 against the board median). Lowest-ranked: Hook Strength (82.0, 25th of 135 configurations, +2.8 against the board median).
- ScriptsFrom 82.8 on Script 10 (engineering process walkthrough) to 86.2 on Script 9 (career guide): a 3.4-point spread across the 10 reference scripts.
- ConsistencyIts Writing Score moves ± 1.1 between drafts of the same script, against ± 2.7 for the median configuration: steadier than most.
- ValueClaude Opus 5.5 (xhigh) ranks higher and costs about $1.00 per script, against $3.56 per script for this one.
Louis's PickOf the two Claude Fable 5.1 settings, this is the one I'd use. If you're not tied to Claude Fable 5.1, Claude Opus 5.5 (xhigh) ranks clearly higher for no more per script.
More Context Behind These Results
Writing Elo comes from comparing its average on each script with every other configuration's average on that same script; a gap smaller than the draft-to-draft variation counts as a draw (what the ranges can and cannot show).
On Tone & Voice Match, its best-ranked metric, its drafts sound closer to Louis's voice than the typical configuration's. Even its lowest-ranked metric, Hook Strength, ranks in the top half of the board, so no metric stands out as a weak spot.
The script format moves its score. If most of your scripts look like its best or weakest format, that result is a better guide than the average.
Its drafts vary little, so the first draft is usually close to the next one.
Among proprietary models, Claude Fable 5.1 is 2nd of 48. As a configuration, it is 3rd of 92 proprietary configurations. It also sits above every open-weight configuration; the best of them, GLM-5.3 (max), is configuration #16.
All Settings of Claude Fable 5.1
Claude Fable 5.1 is also on the board at other effort settings, and none of them rank above this one. The thinking-level page for Claude Fable 5.1 charts how quality, cost and time change with the setting.
| Setting | Configuration Rank | Writing Score | Writing Elo | Cost / Script | Time / Script |
|---|---|---|---|---|---|
| max effort this page | #3 | 84.5 | 2543 | $3.56 | 12.3 min |
| high | #9 | 83.4 | 2333 | $1.85 | 6.3 min |
Skill Profile Across the Nine Metrics
Each corner is one metric on a 0 to 100 scale; the further out, the higher the score. A corner outside the dashed line beats the board median. Hover or tap a point for its exact score, and a metric name for what it rewards.
Scores by Metric
Nine metrics, each scored 0 to 100 and weighted into the Writing Score; the weight sits under each name. Rank is out of all 135 ranked configurations.
Scores by Reference Script
Every ranked configuration writes five drafts for each of the same 10 briefs, and each score is the mean of those drafts. The rank and board median compare it with every configuration on that script, which separates a weak result from a hard script. The result on the format closest to your own work is the most relevant.
Consistency Between Drafts
Every score on this page is the mean of 5 drafts per script. The ± is the standard deviation between those drafts: the larger it is, the more two drafts of the same script can differ.
Compared with the typical model, it's steadiest on Length Adherence: ± 0.8 between drafts against ± 7.0.
Consistency by Metric
| Metric | This model | Board median | Verdict |
|---|---|---|---|
| Tone & Voice Match ? | 81.8 ± 1.0 | ± 2.0 | steadier than most |
| Writing Craft & Clarity ? | 80.8 ± 1.1 | ± 1.6 | typical |
| Substance, Accuracy & Value ? | 86.0 ± 1.3 | ± 2.3 | steadier than most |
| Continuity & Emotion ? | 84.5 ± 0.9 | ± 1.5 | steadier than most |
| YouTube Best Practices ? | 83.7 ± 1.7 | ± 2.5 | typical |
| Hook Strength ? | 82.0 ± 2.1 | ± 2.8 | typical |
| Length Adherence ? | 98.3 ± 0.8 | ± 7.0 | steadier than most |
| Slop Score ? | 86.8 ± 0.9 | ± 1.6 | steadier than most |
| Visual Cue Quality ? | 82.7 ± 1.5 | ± 3.0 | steadier than most |
Cost, Time and Tokens per Script
Logged on every run; none of these figures affects the Writing Score. Time is the average time to one accepted script, retries included. Cost is one script at the API list price.
Scores by Judge
Four judges score the same 50 stored drafts blind against the same rubric: three LLM judges from three labs, plus Jev, a typed judge from TypeSafe that rates each metric on five described quality levels. No single judge's taste decides the result. The Writing Score of 84.5 combines their scores with the parts computed in code (Length Adherence and half of the Slop Score). The highest and lowest judge are 10.6 points apart on its Writing Score. That is close to the board median of 13.7. Each judge also has its own scale, so every card shows that judge's score against its average across the board. How the panel works.
Evaluation Setup
How this exact configuration was run and judged: route, model ID, dates, sampling and prompt.
- Accessed viaClaude Code (Anthropic subscription).
- Exact model / route id
claude-fable-5-1atreasoning level: max. - Generations5 independent runs × 10 scripts = 50 drafts, stored after generation and never edited.
- Run dates2026-10-08 to 2026-10-11.
- JudgesClaude Opus 5.5 at medium effort through the Claude Code subscription, GPT-6.1 Sol at medium reasoning through the Codex CLI, GLM 5.3 Flash through OpenRouter, and Jev 1.13 from TypeSafe. One call per judge per draft. All four score every draft on their own, blind to which model wrote it. The three LLM judges use the identical rubric and have to quote evidence before they score a metric. Jev answers the same rubric as one question per metric, choosing among five described quality levels, and writes no text. Seven metrics are the plain average of the four judges. Length is computed from the spoken word count, and Slop is half computed (lexical scans minus the spoken-dash penalty) and half judged. The Writing Elo is cross-checked with a Bradley-Terry fit of the same pairwise results (methodology).
- Sampling and promptThe provider's default sampling, with no fine-tuning and no system-prompt changes. Every current-ranked model gets the same prompt, about 13,000 tokens (the count shifts a bit with each model's tokenizer): a style guide built from Louis's voice and storytelling guides, the target length, and the brief with its research packet. Generation is closed-book on every route: the prompt is the only source, with no web search, browsing, code execution, file access or other tool (generation).
- What stays privateThe exact rubric and any non-public reference material. Each script is normally benchmarked before its video is published, which lowers the odds that a model has seen the reference, though it does not rule it out (why).
Frequently Asked Questions
How Good Is Claude Fable 5.1 (max effort) at Writing?
Claude Fable 5.1 ranks #2 of 82 models on ToneBench, and this is its best configuration. This configuration is #3 of 135 configurations, near the top of the board, with a Writing Elo of 2543 and a Writing Score of 84.5/100. The ranks come from full YouTube scripts written in the voice of Louis-François Bouchard and judged blind, with the channel's finished script as the reference. The benchmark measures long-form scripted writing, so the result does not carry over to every kind of text.
Is Claude Fable 5.1 (max effort) the Best Anthropic Model for Writing?
Not quite. Claude Fable 5.1 is 2nd of 12 Anthropic models. The top one is Claude Opus 5.5, through Claude Opus 5.5 (xhigh), about 235 Elo ahead of this setting.
Is Claude Fable 5.1 (max effort) Good Value for the Money?
It costs about $3.56 per script. Claude Opus 5.5 (xhigh) ranks higher and costs less.
What Are the Strengths and Weaknesses of Claude Fable 5.1 (max effort)?
Its best-ranked metric is Tone & Voice Match (81.8, 3rd of 135 configurations, +8.4 against the board median), and its lowest-ranked is Hook Strength (82.0, 25th of 135, +2.8). Even that one ranks in the top half of the board. The Scores by Metric section shows the board median and the board's best for each one.
How Was Claude Fable 5.1 (max effort) Evaluated?
It was run through Claude Code (Anthropic subscription), with the exact model/route ID claude-fable-5-1 at reasoning effort max, first run on 2026-10-08. It wrote each script 5 times with the provider's default sampling and no fine-tuning. The Evaluation Setup section and the methodology page have the details.
Does Claude Fable 5.1 (max effort) Have Open Weights?
No. It is a proprietary model: its weights are not public. Among proprietary configurations it is 3rd of 92 for writing.