Model Comparison
Claude Opus 5 vs Claude Fable 5
Too close to call: the best configurations, Claude Opus 5 (max effort) and Claude Fable 5 (max effort, Opus 4.8 fallback), are 80 Elo apart, and their 95% ranges overlap. Among 78 models, each ranked by its best configuration, Claude Opus 5 is #5 and Claude Fable 5 is #6. Cost per script: $0.736 for Claude Opus 5 (max effort) and $3.20 for Claude Fable 5 (max effort, Opus 4.8 fallback).
Last updated , from board data generated at 01:13 UTC.
Picks and Verdict
PickClaude Opus 5
Claude Opus 5 (max effort)
Pick Claude Opus 5 (max effort) for the script itself, since it has the highest Writing Elo and the steadiest drafts on this page, at $0.736 a script against $3.20 for Fable's best.
PickClaude Fable 5
Claude Fable 5 (high)
Pick Claude Fable 5 (high) when hitting the target length matters most, since it has the best length score on this page and the board cannot separate it from the max effort setting, at $1.34 a script against $3.20.
Claude Fable 5 is the expensive model on this page, and at both level names it's the one that rates lower. By best setting, Claude Opus 5 is the #5 model of 78 and Claude Fable 5 the #6 model. Claude Opus 5 (max effort) and Claude Fable 5 (max effort, Opus 4.8 fallback) sit 80 Elo apart with overlapping 95% ranges, so the board cannot separate them. The high settings overlap too. So the bill makes the call. Opus 5 at max effort costs $0.736, and Fable at max costs over four times that and takes over twice as long. Claude Opus 5 (high) can't be separated from Fable's best either, at about a seventh of the price. Neither top step is confirmed: max effort adds 91 Elo on Opus for about 1.6 times the cost and 83 on Fable for 2.4 times, both inside overlapping ranges. To be fair to Fable, its max setting has the best continuity and YouTube best practices scores here. It loses me on the hook, over four points behind Opus at max. My scripts would still go to Opus 5 at max effort.
Disclosure: both models come from the same lab as one of the four judges, Claude Opus 5.5. The other judges sit outside that lab, so 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 Opus 5 and Claude Fable 5, scored on the same 10 scripts by the same four judges.
- 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).
Shaded rows are the configurations chosen for the metric comparison below.
| Configuration | Writing Elo | 95% Range | Writing Score | Cost / Script | Time / Script | Configuration Rank |
|---|---|---|---|---|---|---|
| Claude Opus 5 (max effort) | 2319 | 2260 to 2361 | 83.3 | $0.736 | 5.5 min | #11 |
| Claude Fable 5 (max effort, Opus 4.8 fallback) | 2239 | 2186 to 2298 | 82.9 | $3.20 | 12.5 min | #12 |
| Claude Opus 5 (high) | 2228 | 2180 to 2278 | 82.6 | $0.472 | 3.5 min | #13 |
| Claude Fable 5 (high) | 2156 | 2102 to 2204 | 81.9 | $1.34 | 4.9 min | #22 |
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.
- Best Configurations Head to Head. Claude Opus 5 (max effort) at Elo 2319 (range 2260 to 2361) and Claude Fable 5 (max effort, Opus 4.8 fallback) at Elo 2239 (range 2186 to 2298) have overlapping 95% ranges, so the board cannot separate the two best configurations.
- Lowest Thinking Levels Head to Head. At their lowest thinking levels, Claude Opus 5 (high) at Elo 2228 and $0.472 per script leads Claude Fable 5 (high) at Elo 2156 and $1.34 per script by 72 Elo. Their 95% ranges overlap, so the board cannot separate them.
- Same Level Name, Side by Side. Claude Opus 5 has the higher Writing Elo at every level name both models use: high and max. The 95% ranges overlap at every one of them. Level names come from each provider, so the same name does not promise the same reasoning budget.
- Cheapest Configuration Overlapping the Top One. Claude Opus 5 (high), at $0.472 per script, is the cheapest configuration whose 95% range overlaps that of Claude Opus 5 (max effort), at $0.736 per script: 2180 to 2278 against 2260 to 2361, so the board cannot separate them. Claude Opus 5 (max effort) costs about 1.6 times as much per script.
- Cheapest Claude Opus 5 Configuration Above Claude Fable 5's Best. The cheapest Claude Opus 5 configuration with a higher Writing Elo than Claude Fable 5 (max effort, Opus 4.8 fallback), at Elo 2239 and $3.20 per script, is Claude Opus 5 (max effort), at Elo 2319 and $0.736 per script. Their 95% ranges overlap, so the board cannot separate them. It costs less than the configuration it beats.
- Lowest to Highest Thinking Level. Claude Opus 5 moves +91 Elo from high to max effort, at about 1.6 times the cost per script. Claude Fable 5 moves +83 Elo from high to max effort, at about 2.4 times the cost per script.
Writing Elo at Each Shared Level Name
| Level | Claude Opus 5 | Claude Fable 5 | Gap | 95% Ranges |
|---|---|---|---|---|
| high | 2228 | 2156 | +72 | Overlap |
| max | 2319 | 2239 | +80 | Overlap |
Gap is Claude Opus 5 minus Claude Fable 5 at the same level name, using each model's highest-rated configuration at that level.
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 Opus 5 (max effort) scores higher on four of the nine metrics and Claude Fable 5 (max effort, Opus 4.8 fallback) on five. Weighted by each metric's share of the Writing Score, Hook Strength does the most to put Claude Opus 5 (max effort) ahead, with a 4.3-point lead on that metric. The weight beside each metric is its share of the Writing Score.
Consistency Across Drafts
| Claude Opus 5 (max effort) | Claude Fable 5 (max effort, Opus 4.8 fallback) | |
|---|---|---|
| Score spread across drafts (±) | 1.10 | 1.96 |
| Lowest script score | 81.9 Script 10 | 81.2 Script 8 |
| Highest script score | 84.5 Script 7 | 86.4 Script 7 |
| Range across scripts | 2.6 | 5.2 |
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 Opus 5 (max effort) minus Claude Fable 5 (max effort, Opus 4.8 fallback), and the higher score is in bold.
| Script | Claude Opus 5 (max effort) | Claude Fable 5 (max effort, Opus 4.8 fallback) | Gap |
|---|---|---|---|
| Script 1 opinion / warning explainer | 83.0 | 83.1 | -0.1 |
| Script 2 news-analysis / skeptical explainer | 83.4 | 83.7 | -0.3 |
| Script 3 personal roadmap / opinion | 83.2 | 81.6 | +1.6 |
| Script 4 short explainer | 83.2 | 81.6 | +1.6 |
| Script 5 news-analysis / opinion explainer | 83.3 | 82.5 | +0.8 |
| Script 6 founder announcement / personal origin story | 83.4 | 82.9 | +0.5 |
| Script 7 personal technical walkthrough / agentic workflow case study | 84.5 | 86.4 | -1.9 |
| Script 8 product release announcement / personal observation | 83.0 | 81.2 | +1.8 |
| Script 9 career guide / hiring analysis | 83.6 | 83.2 | +0.4 |
| Script 10 engineering process walkthrough / presentation adaptation | 81.9 | 82.8 | -0.9 |
Scorecards and Thinking Pages
Each configuration name in the table above opens its own scorecard.
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.
← All comparisons