Calibration · Evaluation · Decision models

JEV calibration leaderboard

Whether Jev, thirteen other hosted decision models and eight open-weight ones are right as often as they say they are, all asked the same exam-style questions.

Twenty-three decision models, scored on accuracy, expected calibration error (ECE) and the Brier score. Every model was asked exactly the same questions. Pick a dataset to see every model on it, or a model to see its reliability diagram.

RankModelAccuracy ↑ECE ↓Brier score ↓
11 ⊸ 5Perplexity Decider v1.2Perplexity · API only86.1% ±1.0%0.046 ±0.0080.080 ±0.005
21 ⊸ 8d1-ultraLiquid AI · API only85.7% ±1.0%0.045 ±0.0070.084 ±0.004
31 ⊸ 8Jev 1.13TypeSafe · API only86.9% ±1.0%0.046 ±0.0070.085 ±0.005
41 ⊸ 8Jev 1.14TypeSafe · API only86.7% ±1.0%0.047 ±0.0070.087 ±0.005
51 ⊸ 8Clef OmniCloudflare · API only84.9% ±1.1%0.068 ±0.0080.088 ±0.005
62 ⊸ 8ClefCloudflare · API only84.7% ±1.1%0.048 ±0.0070.090 ±0.005
72 ⊸ 8Clef FlashCloudflare · API only83.5% ±1.1%0.057 ±0.0070.090 ±0.004
82 ⊸ 8Drex MaxNace AI · API only85.9% ±1.1%0.062 ±0.0090.090 ±0.006
99Drex v2.0Nace AI · API only81.4% ±1.1%0.058 ±0.0070.102 ±0.004
1010 ⊸ 13JEV-27BAutoTrust AI · Apache-2.079.5% ±1.1%0.068 ±0.0080.112 ±0.004
1110 ⊸ 14Perplexity Decider Flash v1.2Perplexity · API only80.2% ±1.1%0.070 ±0.0090.115 ±0.006
1210 ⊸ 14GPT-6 Luna DecisionsOpenAI · API only80.1% ±1.1%0.057 ±0.0080.115 ±0.005
1310 ⊸ 15Mercury DecideInception · API only80.5% ±1.0%0.104 ±0.0090.120 ±0.007
1411 ⊸ 16Drex v1.5Nace AI · API only77.8% ±1.1%0.087 ±0.0110.126 ±0.006
1513 ⊸ 17JPT-4Bkirp · CC BY-NC 4.075.2% ±1.3%0.064 ±0.0090.131 ±0.005
1614 ⊸ 17JEV-9BAutoTrust AI · Apache-2.074.0% ±1.1%0.070 ±0.0090.136 ±0.005
1715 ⊸ 19Solar DecideUpstage · API only80.2% ±1.2%0.113 ±0.0100.141 ±0.008
1817 ⊸ 19Kev-4BJared Palmer · Apache-2.072.1% ±1.2%0.087 ±0.0090.147 ±0.004
1917 ⊸ 21Solar Decide FlashUpstage · API only71.5% ±1.2%0.070 ±0.0100.155 ±0.005
2019 ⊸ 21Qwen3.5-9B, untrainedAlibaba Qwen · Apache-2.070.5% ±1.2%0.124 ±0.0100.162 ±0.003
2119 ⊸ 21Strands Decider 2BAmazon Strands Labs · Apache-2.066.8% ±1.2%0.089 ±0.0100.164 ±0.005
2222Open-Jev-2BZefan Cai · Apache-2.058.3% ±1.3%0.142 ±0.0100.213 ±0.004
2323LayaConvai Innovations · Apache-2.040.8% ±1.1%0.164 ±0.0110.233 ±0.005

Means over the eight datasets every model could be asked: Under Pressure with 4 and with 16 options, MMLU, ARC-Challenge, CommonsenseQA, OpenBookQA, TruthfulQA and GPQA. GPT-6 Luna Decisions would not answer 5 of these questions, which its scores leave out. Ranked by Brier score. Each ± and error bar is the 95% interval from resampling questions, and the small numbers under each rank are the range of ranks those intervals allow.

Reliability diagram

Among questions where a model stated a given confidence, how often it was right. Bars show the share answered correctly, the dark tick on each bar is the confidence the model stated, and the dashed diagonal is perfect calibration.

What we found

Perplexity’s Decider is the one to beat. It tops this board and the decision benchmarks. Jev is near the top here, on exam questions, but lands in the middle of the pack on decision questions.

Jev knows when it is right. Its open copies are less sure of that. Jev’s confidence matches its accuracy on every standard exam set, from easy ones like ARC to the very hard GPQA. JEV-9B and JEV-27B were trained to copy Jev’s answers, and they undersell themselves on easy questions and oversell on hard ones. Our guess is that they learned how confident Jev is, and that much confidence is too much for a smaller model that knows less.

Training on Jev’s answers makes a model bolder everywhere. The untrained Qwen model is too timid almost across the board. After training, the middle of the range looks right, easy sets stay a little timid, and the hardest set tips into overconfidence. Kev, JPT, Strands Decider and Open-Jev were trained on their own data and lean the same way. Laya, a small encoder, is overconfident almost everywhere.

Some blind spots are shared, Jev included. When the right answer is buried among many options, as in Under Pressure, most models are surer than they should be. d1-ultra is the steadiest model we tested: no dataset pushes its confidence far from its accuracy.

Solar Decide sounds the most certain without earning it, with Mercury Decide close behind.

What it means in practice. If you act on every answer above a fixed confidence, you will let through more mistakes on hard questions than on easy ones, and how many depends on the model. Check calibration on your own task, or use conformal prediction, which keeps its guarantee even when the probabilities are off.

Models

Fifteen models are hosted: TypeSafe’s Jev 1.13 and 1.14 and thirteen decision models from Perplexity, Nace AI, Liquid AI, OpenAI, Cloudflare, Inception and Upstage. We asked them through OpenRouter in October 2026, each pinned to its maker’s own servers. Each name links to the model’s OpenRouter page.

Eight models have open weights. JEV-9B and JEV-27B are AutoTrust’s open copies of Jev, trained on Jev 1.13’s answers. Qwen3.5-9B, untrained, is the same base model read out the same way without that training. The rest are Jev-style models from other teams, each run through the server its authors ship. Each name links to its model card. Open models were asked with lettered options, the format Jev’s documentation uses, so a model tuned to another format may score a little lower here than in its authors’ own tests.

Same questions for everyone

MMLU and MMLU-Pro are cut to 2,000 questions each and BANKING77 to 1,000, sampled in proportion to subject. Every other dataset is used in full. A few models could not answer everything:

  • Solar Decide and Solar Decide Flash take at most 26 options, so they skipped Under Pressure at 64 options and BANKING77.
  • GPT-6 Luna Decisions refused 5 questions in the summary datasets.
  • JEV-27B ran out of GPU memory on MMLU-Pro, BANKING77 and Under Pressure at 64 options.

None of those datasets are in the summary. Jev and GPT-6 Luna round their probabilities to two decimals, which barely moves accuracy, ECE or the Brier score.

Data

Every number on this page comes from these files, under CC BY 4.0.

Changelog

  • Added Jev 1.13, Jev 1.14 and thirteen other hosted decision models; every model is now scored on the same questions.
  • First published.

Discussion

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