Model Comparison
Claude Opus 5 vs DeepSeek V4.1 Flash
Claude Opus 5 (max effort) leads DeepSeek V4.1 Flash (max) by 279 Elo, and their 95% ranges sit 184 Elo apart. Even Claude Opus 5's lowest-rated configuration, Claude Opus 5 (high), ranks above DeepSeek V4.1 Flash (max). Among 78 models, each ranked by its best configuration, Claude Opus 5 is #5 and DeepSeek V4.1 Flash is #14. Cost per script: $0.736 for Claude Opus 5 (max effort) and $0.017 for DeepSeek V4.1 Flash (max).
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) when the script matters, since it leads DeepSeek's best by 279 Elo at $0.736 a script.
PickDeepSeek V4.1 Flash
DeepSeek V4.1 Flash (high)
Pick DeepSeek V4.1 Flash (high) for bulk drafting at $0.012 a script, a setting the board can't separate from max.
Every Claude Opus 5 setting rates above every DeepSeek V4.1 Flash setting, so this page comes down to price. Claude Opus 5 is the #5 model on the board and DeepSeek V4.1 Flash the #14 model, with each of the 78 models ranked by its best setting. Claude Opus 5 (max effort) leads DeepSeek V4.1 Flash (max) by 279 Elo with separate 95% ranges, and it costs $0.736 a script against $0.017, about 43 times as much. Neither model's top step is confirmed. On Opus, max effort adds 91 Elo over high for about 1.6 times the cost, and those two ranges overlap. On DeepSeek, thinking is worth 402 Elo across its ladder, from no thinking to max, but the top two ranges overlap too, and DeepSeek V4.1 Flash (high) costs $0.012 and finishes in about a minute. Both of those DeepSeek settings land closer to the requested length than either Opus setting, and DeepSeek at max gives steadier drafts than Opus at high. I'd still pay for Opus at max effort when the script matters, and run DeepSeek at high when I need lots of drafts for almost nothing.
Disclosure: Claude Opus 5 comes from the same lab as one of the four judges, Claude Opus 5.5. The other three sit outside its lab, so it is never 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 DeepSeek V4.1 Flash, 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 | Reasoning Tokens | Configuration Rank |
|---|---|---|---|---|---|---|---|
| Claude Opus 5 (max effort) | 2319 | 2260 to 2361 | 83.3 | $0.736 | 5.5 min | N/A | #11 |
| Claude Opus 5 (high) | 2228 | 2180 to 2278 | 82.6 | $0.472 | 3.5 min | N/A | #13 |
| DeepSeek V4.1 Flash (max) | 2040 | 1999 to 2076 | 81.0 | $0.017 | 2.4 min | 22,010 | #28 |
| DeepSeek V4.1 Flash (high) | 1971 | 1925 to 2010 | 80.3 | $0.012 | 1.1 min | 13,809 | #38 |
| DeepSeek V4.1 Flash (low) | 1856 | 1815 to 1906 | 79.3 | $0.0077 | 0.7 min | 6,740 | #46 |
| DeepSeek V4.1 Flash (no thinking) | 1638 | 1588 to 1680 | 76.8 | $0.0037 | 0.3 min | 0 | #61 |
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. N/A under Reasoning Tokens means the board has no separate reasoning count for that route.
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) leads DeepSeek V4.1 Flash (max) by 279 Elo, and their 95% ranges do not overlap (2260 to 2361 against 1999 to 2076), which is strong evidence for that order.
- Every Claude Opus 5 Configuration Ranks Higher. Both Claude Opus 5 configurations rank above all four DeepSeek V4.1 Flash configurations: the lowest-rated, Claude Opus 5 (high) at Elo 2228, still beats DeepSeek V4.1 Flash (max) at Elo 2040. Their 95% ranges do not overlap.
- Lowest Thinking Levels Head to Head. At their lowest thinking levels, Claude Opus 5 (high) at Elo 2228 and $0.472 per script leads DeepSeek V4.1 Flash (no thinking) at Elo 1638 and $0.0037 per script by 590 Elo. Their 95% ranges do not overlap.
- 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 do not overlap at any 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 DeepSeek V4.1 Flash's Best. The cheapest Claude Opus 5 configuration with a higher Writing Elo than DeepSeek V4.1 Flash (max), at Elo 2040 and $0.017 per script, is Claude Opus 5 (high), at Elo 2228 and $0.472 per script. It costs about 28 times as much per script.
- 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. DeepSeek V4.1 Flash moves +402 Elo from no thinking to max, at about 4.6 times the cost per script.
Writing Elo at Each Shared Level Name
| Level | Claude Opus 5 | DeepSeek V4.1 Flash | Gap | 95% Ranges |
|---|---|---|---|---|
| high | 2228 | 1971 | +257 | Separate |
| max | 2319 | 2040 | +279 | Separate |
Gap is Claude Opus 5 minus DeepSeek V4.1 Flash 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 eight of the nine metrics and DeepSeek V4.1 Flash (max) on one. Weighted by each metric's share of the Writing Score, Tone & Voice Match does the most to put Claude Opus 5 (max effort) ahead, with a 2.7-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) | DeepSeek V4.1 Flash (max) | |
|---|---|---|
| Score spread across drafts (±) | 1.10 | 1.30 |
| Lowest script score | 81.9 Script 10 | 79.7 Script 10 |
| Highest script score | 84.5 Script 7 | 82.4 Script 7 |
| Range across scripts | 2.6 | 2.7 |
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 DeepSeek V4.1 Flash (max), and the higher score is in bold.
| Script | Claude Opus 5 (max effort) | DeepSeek V4.1 Flash (max) | Gap |
|---|---|---|---|
| Script 1 opinion / warning explainer | 83.0 | 80.8 | +2.2 |
| Script 2 news-analysis / skeptical explainer | 83.4 | 81.2 | +2.2 |
| Script 3 personal roadmap / opinion | 83.2 | 81.2 | +2.0 |
| Script 4 short explainer | 83.2 | 80.1 | +3.1 |
| Script 5 news-analysis / opinion explainer | 83.3 | 81.1 | +2.2 |
| Script 6 founder announcement / personal origin story | 83.4 | 80.8 | +2.6 |
| Script 7 personal technical walkthrough / agentic workflow case study | 84.5 | 82.4 | +2.1 |
| Script 8 product release announcement / personal observation | 83.0 | 80.7 | +2.3 |
| Script 9 career guide / hiring analysis | 83.6 | 82.2 | +1.4 |
| Script 10 engineering process walkthrough / presentation adaptation | 81.9 | 79.7 | +2.2 |
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.
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