Model Comparison
GPT-5.6 Terra vs DeepSeek V4 Pro 0813
GPT-5.6 Terra (ultra) leads DeepSeek V4 Pro 0813 (max) by 124 Elo, and their 95% ranges sit 46 Elo apart. Among 78 models, each ranked by its best configuration, GPT-5.6 Terra is #13 and DeepSeek V4 Pro 0813 is #21. Cost per script: $0.275 for GPT-5.6 Terra (ultra) and $0.077 for DeepSeek V4 Pro 0813 (max).
Last updated , from board data generated at 01:13 UTC.
Picks and Verdict
PickGPT-5.6 Terra
GPT-5.6 Terra (medium)
Pick GPT-5.6 Terra (medium) for everyday drafts, since the board can't separate it from DeepSeek's best and it takes 1.4 minutes for $0.062 a script.
PickDeepSeek V4 Pro 0813
DeepSeek V4 Pro 0813 (max)
Pick DeepSeek V4 Pro 0813 (max) when consistency matters more than speed, since its drafts are steadier than GPT-5.6 Terra (medium) and land 6.3 points closer to the requested length for $0.077 a script.
Terra's cheap setting keeps pace with DeepSeek's most expensive one. GPT-5.6 Terra (medium) sits 48 Elo above DeepSeek V4 Pro 0813 (max), and their 95% ranges overlap, so the board can't separate the two. They get there differently. Medium is Terra's lower setting, at $0.062 a script and 1.4 minutes. Max is DeepSeek's top one, at $0.077 and 8.9 minutes, more than six times the wait. GPT-5.6 Terra (ultra) is the setting that clears DeepSeek, by 124 Elo with separate ranges, and it makes GPT-5.6 Terra the #13 model of 78 against the #21 model, each ranked by its best setting. Ultra's range overlaps medium's and it costs about 4.4 times as much, so I wouldn't pay that. DeepSeek is the reverse case. Its high setting sits 600 Elo lower, so max is the only one I'd consider. DeepSeek at max does land closer to the requested length than Terra at medium, by 6.3 points, and its drafts are a little steadier. Terra at medium has the edge on tone and substance, by 2.3 and 2.9 points. For under a fifth of the wait, I'd run Terra at medium.
Disclosure: GPT-5.6 Terra comes from the same lab as one of the four judges, GPT-6.1 Sol. 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 GPT-5.6 Terra and DeepSeek V4 Pro 0813, 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 |
|---|---|---|---|---|---|---|---|
| GPT-5.6 Terra (ultra) | 2074 | 2035 to 2113 | 81.4 | $0.275 | 8.0 min | N/A | #25 |
| GPT-5.6 Terra (medium) | 1998 | 1952 to 2041 | 80.7 | $0.062 | 1.4 min | N/A | #33 |
| DeepSeek V4 Pro 0813 (max) | 1950 | 1906 to 1989 | 80.1 | $0.077 | 8.9 min | 31,573 | #40 |
| DeepSeek V4 Pro 0813 (high) | 1350 | 1272 to 1428 | 72.3 | $0.031 | 1.3 min | 8,879 | #81 |
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. GPT-5.6 Terra (ultra) leads DeepSeek V4 Pro 0813 (max) by 124 Elo, and their 95% ranges do not overlap (2035 to 2113 against 1906 to 1989), which is strong evidence for that order.
- Lowest Thinking Levels Head to Head. At their lowest thinking levels, GPT-5.6 Terra (medium) at Elo 1998 and $0.062 per script leads DeepSeek V4 Pro 0813 (high) at Elo 1350 and $0.031 per script by 648 Elo. Their 95% ranges do not overlap.
- Cheapest Configuration Overlapping the Top One. GPT-5.6 Terra (medium), at $0.062 per script, is the cheapest configuration whose 95% range overlaps that of GPT-5.6 Terra (ultra), at $0.275 per script: 1952 to 2041 against 2035 to 2113, so the board cannot separate them. GPT-5.6 Terra (ultra) costs about 4.4 times as much per script.
- Cheapest GPT-5.6 Terra Configuration Above DeepSeek V4 Pro 0813's Best. The cheapest GPT-5.6 Terra configuration with a higher Writing Elo than DeepSeek V4 Pro 0813 (max), at Elo 1950 and $0.077 per script, is GPT-5.6 Terra (medium), at Elo 1998 and $0.062 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. GPT-5.6 Terra moves +76 Elo from medium to ultra, at about 4.4 times the cost per script. DeepSeek V4 Pro 0813 moves +600 Elo from high to max, at about 2.5 times the cost per script.
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
GPT-5.6 Terra (ultra) scores higher on eight of the nine metrics, and the other one is a tie. Weighted by each metric's share of the Writing Score, Substance, Accuracy & Value does the most to put GPT-5.6 Terra (ultra) ahead, with a 4.7-point lead on that metric. The weight beside each metric is its share of the Writing Score.
Consistency Across Drafts
| GPT-5.6 Terra (ultra) | DeepSeek V4 Pro 0813 (max) | |
|---|---|---|
| Score spread across drafts (±) | 1.38 | 1.48 |
| Lowest script score | 79.8 Script 4 | 78.2 Script 10 |
| Highest script score | 83.0 Script 6 | 81.5 Script 6 |
| Range across scripts | 3.2 | 3.3 |
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 GPT-5.6 Terra (ultra) minus DeepSeek V4 Pro 0813 (max), and the higher score is in bold.
| Script | GPT-5.6 Terra (ultra) | DeepSeek V4 Pro 0813 (max) | Gap |
|---|---|---|---|
| Script 1 opinion / warning explainer | 81.1 | 79.5 | +1.6 |
| Script 2 news-analysis / skeptical explainer | 82.1 | 80.6 | +1.5 |
| Script 3 personal roadmap / opinion | 82.5 | 80.8 | +1.7 |
| Script 4 short explainer | 79.8 | 78.5 | +1.3 |
| Script 5 news-analysis / opinion explainer | 82.2 | 80.9 | +1.3 |
| Script 6 founder announcement / personal origin story | 83.0 | 81.5 | +1.5 |
| Script 7 personal technical walkthrough / agentic workflow case study | 80.6 | 81.1 | -0.5 |
| Script 8 product release announcement / personal observation | 80.3 | 80.2 | +0.1 |
| Script 9 career guide / hiring analysis | 81.8 | 79.9 | +1.9 |
| Script 10 engineering process walkthrough / presentation adaptation | 80.6 | 78.2 | +2.4 |
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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