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Model Comparison

Claude Fable 5 vs GPT-6 Astra

Too close to call: the best configurations, Claude Fable 5 (max effort, Opus 4.8 fallback) and GPT-6 Astra (max), are 54 Elo apart, and their 95% ranges overlap. Among 78 models, each ranked by its best configuration, Claude Fable 5 is #6 and GPT-6 Astra is #11. Cost per script: $3.20 for Claude Fable 5 (max effort, Opus 4.8 fallback) and $1.15 for GPT-6 Astra (max).

Last updated , from board data generated at 01:13 UTC.

Claude Fable 5
2239 Writing Elo of Claude Fable 5 (max effort, Opus 4.8 fallback), its best configuration#6 of 78 models · 82.9/100 Writing Score · $3.20 per script2 configurations on the board
GPT-6 Astra
2185 Writing Elo of GPT-6 Astra (max), its best configuration#11 of 78 models · 82.3/100 Writing Score · $1.15 per script2 configurations on the board

Picks and Verdict

PickClaude Fable 5

Claude Fable 5 (high)

Pick Claude Fable 5 (high) when voice and video structure matter most, since its range overlaps the max effort setting's and it costs $1.34 instead of $3.20.

PickGPT-6 Astra

GPT-6 Astra (max)

Pick GPT-6 Astra (max) for an explainer where the hook and the facts carry it, at $1.15 a script against $3.20 for Fable's best, with ranges that overlap.

Three settings on this page have 95% ranges that overlap, and they cost $3.20, $1.34 and $1.15 a script. Claude Fable 5 is the #6 model on the board and GPT-6 Astra the #11 model, with each of the 78 models ranked by its best setting. Claude Fable 5 (max effort, Opus 4.8 fallback) rates highest, 54 Elo above GPT-6 Astra (max), but the board can't separate those two, and it can't separate either from Claude Fable 5 (high). So I'd choose by the kind of draft I need. Fable sounds more like me and builds the video better: about three points up on tone at max effort, and more than six on YouTube Best Practices at either setting. Astra at max opens stronger and leads on substance, length and slop. It needs that top setting, though: GPT-6 Astra (medium) falls below both Fable settings, with ranges that don't overlap. For an explainer I'd run Astra at max, the cheapest of the three. When the voice matters most, I'd pay a little more for Fable at high, which takes under five minutes where max effort takes over twelve.

Disclosure: Claude Fable 5 and GPT-6 Astra each come from the same lab as one of the judges (Claude Opus 5.5 and GPT-6.1 Sol). Neither is scored by its own lab alone (how the panel works). The judge analysis measures how much each judge favors its own lab.

How to Read the Writing Score, Writing Elo and 95% Ranges

Writing Score and Writing Elo. The Writing Score (0 to 100) is the weighted average of the nine metric scores: seven from the judges, Length Adherence from code and the Slop Score half from each. The Writing Elo is a rating from pairwise comparisons: on each script, each configuration's average across its drafts is compared with every other configuration's, and gaps within the draft-to-draft variation count as draws. Elo rewards winning often, so the two can put configurations in a different order.

Elo ranges. Each 95% range shows how far a configuration's Elo could move if the drafts had come out slightly differently. It comes from resampling every configuration's recorded draft scores on each reference script and ranking again. Comparing two separate ranges does not test the Elo gap between them: ranges far apart are strong evidence for the order, and overlapping ranges do not mean a tie. The reference scripts stay fixed, so the ranges say nothing about new scripts. The methodology page has the full description.

All Thinking Levels of Both Models

Every ranked configuration of Claude Fable 5 and GPT-6 Astra, scored on the same 10 scripts by the same four judges.

How to Read the Chart
  • Each row is one configuration: the model at one thinking level. The dot is its Writing Elo, a rating from pairwise comparisons of the scores on each script, and the bar is its 95% range: how far that Elo could move if the drafts had come out slightly differently.
  • When two bars overlap, the board cannot order those two configurations. Bars far apart are strong evidence for the order.
  • The table under the chart lists the same configurations in the same order and adds the Writing Score (the 0 to 100 consensus of the judges and code), cost, time and configuration rank (the place among all configurations on the board).
Claude Fable 5GPT-6 Astra
ConfigurationWriting Elo95% RangeWriting ScoreCost / ScriptTime / ScriptConfiguration Rank
Claude Fable 5 (max effort, Opus 4.8 fallback)22392186 to 229882.9$3.2012.5 min#12
GPT-6 Astra (max)21852145 to 222382.3$1.159.2 min#21
Claude Fable 5 (high)21562102 to 220481.9$1.344.9 min#22
GPT-6 Astra (medium)20031968 to 203580.7$0.2621.5 min#32

Cost is one script at the API list price of the route used, uncached and without judging. Time is the average for one accepted script, retries included.

Computed Findings Across Thinking Levels

Each finding is computed from the configurations above. Where two 95% ranges overlap, the board cannot order those two configurations.

Two Chosen Configurations Compared

Pick one configuration of each model to compare their metric scores, consistency across drafts and per-script scores. Each menu starts on the model's best configuration.

Scores by Metric

Claude Fable 5 (max effort, Opus 4.8 fallback)GPT-6 Astra (max)Solid bar: higher score in that row

Claude Fable 5 (max effort, Opus 4.8 fallback) scores higher on three of the nine metrics and GPT-6 Astra (max) on six. Weighted by each metric's share of the Writing Score, YouTube Best Practices does the most to put Claude Fable 5 (max effort, Opus 4.8 fallback) ahead, with a 7.7-point lead on that metric. The weight beside each metric is its share of the Writing Score.

Tone & Voice Match19% weight
80.6
77.8
Writing Craft & Clarity13% weight
77.5
78.4
Substance, Accuracy & Value15% weight
84.9
87.5
Continuity & Emotion14% weight
84.4
79.9
YouTube Best Practices12% weight
84.3
76.6
Hook Strength10% weight
78.0
82.1
Length Adherence8% weight
94.7
98.3
Slop Score5% weight
84.6
88.6
Visual Cue Quality4% weight
81.2
83.4

Consistency Across Drafts

Claude Fable 5 (max effort, Opus 4.8 fallback)GPT-6 Astra (max)
Score spread across drafts (±)1.961.87
Lowest script score81.2 Script 880.6 Script 1
Highest script score86.4 Script 785.8 Script 9
Range across scripts5.25.2

Spread is how much the Writing Score moves between a configuration's drafts, and lower is steadier. Green marks the better number in each row.

Scores by Script

Writing Score on each reference script. Gap is Claude Fable 5 (max effort, Opus 4.8 fallback) minus GPT-6 Astra (max), and the higher score is in bold.

ScriptClaude Fable 5 (max effort, Opus 4.8 fallback)GPT-6 Astra (max)Gap
Script 1 opinion / warning explainer83.180.6+2.5
Script 2 news-analysis / skeptical explainer83.782.0+1.7
Script 3 personal roadmap / opinion81.684.3-2.7
Script 4 short explainer81.682.7-1.1
Script 5 news-analysis / opinion explainer82.581.3+1.2
Script 6 founder announcement / personal origin story82.983.6-0.7
Script 7 personal technical walkthrough / agentic workflow case study86.481.6+4.8
Script 8 product release announcement / personal observation81.280.6+0.6
Script 9 career guide / hiring analysis83.285.8-2.6
Script 10 engineering process walkthrough / presentation adaptation82.880.7+2.1

Compare With Another Model

Pick a second model. A pair with its own written match-up opens that page, and any other pair opens in the comparison tool.

Nearby Match-Ups by Best Writing Elo

Every configuration wrote five drafts for each of the same 10 briefs, from the same prompt. Generation was closed-book, with the prompt as the only source and no web search or other tools. Each judge scores every draft once: Claude 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, a typed judge from TypeSafe that answers each metric as a multiple-choice question. The channel's finished script is their reference for the voice, and it gets no score on the board itself.

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