MATILDA JEV v1.5 by Maincode

All scores on this card are from the Decision Index 0.3 public suite (the public dataset of the current leaderboard edition).

A BF16 JEV decision model with a 255-option readout. This is the highest-scoring checkpoint in the completed MATILDA JEV experiments as of 9 October 2026: Decision Index 63.47 (0.3 public suite).

The model accepts a state and one or more decision questions. It supports choice, noul (probability of true), and ordinal score. Inference is one forward pass per question; the model has no text-generation head and does not generate a chain of thought. The LoRA updates are already merged into the weights. No adapter merge is required.

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Use Python 3.12 or newer and install PyTorch for your accelerator. The validated cluster environment uses PyTorch 2.14.0, Transformers 5.17.0, and an AMD Instinct MI355X. Other dependencies are listed in requirements-runtime.txt.

import sys
from pathlib import Path
from huggingface_hub import snapshot_download

checkpoint = Path(snapshot_download('Maincode/matilda-jev-v1.5'))
sys.path.insert(0, str(checkpoint / 'runtime'))
from maincode_jev_serve.model import DecisionModel, answer

model = DecisionModel(checkpoint=checkpoint, device='cuda:0')
row = {
    'state': 'The parcel arrived on schedule.',
    'question': {
        'type': 'choice',
        'instructions': 'Classify delivery.',
        'criteria': {'on_time': 'On time', 'late': 'Late'},
    },
}
print(answer(row['question'], model.predict([row])[0]))

The loader uses the custom code bundled in this repository. AutoModel alone loads the backbone; use DecisionModel to include the separate decision head. The package retains the existing MATILDA configuration aliases and the underlying Transformers implementation. Model weights, tokenizer vocabulary, input template, answer codes, readout, and temperature match the evaluated checkpoint.

predict.py accepts JSON lines containing either state + question or state + questions:

{"state":"Two plus two equals four.","questions":{"truth":{"type":"noul","instructions":"Is this statement true?"}}}

python /path/to/downloaded/model/predict.py --device cuda:0 < requests.jsonl

Evaluation

Decision Index 0.3 public suite: 140,178 of 140,178 scored requests answered across 37 benchmarks (kit 62d2f51). Saved predictions were independently rescored with identical results. The full run, including every prediction, is in Maincode/matilda-jev-decision-index under runs/matilda-jev-v1.5/. scores.json in this repository is the earlier 0.2.1 run (62.76), kept for reference.

Jev is the public-suite part of its Decision Index 0.3 board entry (per-benchmark public results, as published in the kit's tests/fixtures/board-0.3.json), not its Full score. MATILDA JEV v1 is Maincode/matilda-jev-v1 (runs/matilda-jev-v1.3/ in the same dataset).

Area scores are chance-corrected skill multiplied by 100. These results are diagnostic: earlier training in this model's lineage used benchmark-related material, and this release was chosen after comparing experimental scores. The numbers are not an independent held-out generalization estimate. The full suite evaluated text decisions; vision inference was not validated for this release.