Rubric Rumble.
Give candidates the same task.
Then open the decision.
A runnable experimental model workbench. Formerly Mortal Kombat. Choose a way in, or inspect the offline replay below.
Below: the offline replay. Its exact-field rules judge is separate from the GPT-5.4 judge in the historical battles.
Same task. Different answers.
One point for each exact field match. Two fields on each of two records: four possible points.
Extract the owner and next action. Return a JSON object with string fields owner and action, preserving the exact wording.
Plain-text fixture Disqualified / not a third-place finish
The response arrived successfully. Validation rejected its shape. This is different from a failed network call.
See the exact disqualification record
One battle. Four observable phases.
These ladder states were observed during an independent replay of the unchanged engine. The phases are not extra battles.
No prior ranking or rates are supplied. The engine sorts these candidates by provider and candidate ID; it does not use their order in the task file.
Excluded from ranking: malformed-fixture
5 captured responses, 4 accepted
The malformed response remains in the evidence but does not increment the engine's successful-evaluation count. Its second artifact is skipped.
Evaluate first, compare second
All candidates pass through output checking before the ladder starts. A valid output is reused during comparisons. This run has zero cache hits.
The judge defines the result
Exact fields decide this fixture. A tie would use candidate ID order, explicitly as a tie-break. A different rubric can reward different behavior.
Take the run with you.
The task, captured result, observed trace, and source hashes travel with this page. No account is needed for the fixture.
git clone https://github.com/CinvanaAI/rubric-rumble.git
cd rubric-rumble
python -m pip install -e .
rubric-rumble demo --out runs/first-evaluationRequires Git and Python 3.11 or newer. If you already have the repository, start inside it with the install command. Open runs/first-evaluation/report.html; result.json is beside it. Choose a new directory for each run.
28129bbae2a0f3413b26f819d4cc32b6c66fb90c84ad3ad6ee37363e498ea276This fingerprints the validated task as sorted-key, compact JSON. It is not the raw task-file hash. Match this value and the outcomes when reproducing; timestamps will differ.
Print the fingerprint from your new result
python -c "import json; print(json.load(open('runs/first-evaluation/result.json'))['task_sha256'])"This page replays saved evidence; it does not call a provider or run Python in your browser. The source links show the snapshot behind this recorded replay. The operating atlas explains the current application.
To supply your own task: rubric-rumble example my-task.json, then rubric-rumble run my-task.json to inspect the plan. Execution is explicit through --execute.