A family of open System One models by Mark Marosi that softmax option-letter logits at an answer slot: decider-0.8b, 2b, 4b and 35b-a3b on Qwen3.5 bases, decider-12b on Gemma-4-12B-it, and training-free readouts of larger chat models. This page carries decider-2b v11.
SimpleJev's LoRA adapters and pointer head that turn an open model into a typed-decision model: given a state, a question and the options, it returns a probability for every option without generating text. This entry is the Qwen3.8-27B release; the others are linked.
Decides
choice, score, noul, classify, route
choice, score, noul
Architecture
decider
jevany
Fine-tuned from
qwen/qwen3.5-2b-base
qwen/qwen3.8-27b
License
apache-2.0
apache-2.0
Availability
Open weights
Open weights
Hosted by
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Input price
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Decision accuracy
75.2%
86.0%
Calibration error
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0.026
Valid action rate
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Median latency
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p95 latency
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Figures are from each model’s manifest; accuracy and latency are what the publishers report, on their own suites and hardware. Add a third model.
Questions
What is the difference between decider and jevany?
decider is from Mapika and jevany from SimpleJev. Both have open weights you can download and run. Both answer choice, score and noul questions. Only decider answers classify and route. decider is the smaller model, at 1.9B parameters to 27B.
Which is more accurate, decider or jevany?
They report on different suites — decider 75.2% on Decider regression set, 28 held-out tasks (decider-2b v11), jevany 86.0% on SimpleJev Transfer suite (1,046 decisions from seven cross-domain datasets plus robustness slices; the maker's own) — so the numbers do not rank them. Test both on your own labelled examples.
Which is cheaper, decider or jevany?
decider: Free (open weights). jevany: Free (open weights). Open weights cost nothing per call beyond your own hardware.
Can I run decider or jevany locally?
Yes, both: systemone pull mapika/decider and systemone pull simplejev/jevany download the weights.
