Overview
What Tarot-Draw is
Tarot-Draw is a family of probability estimators for binary questions about future events.
Give a model a question, its resolution criteria, a scheduled
resolution date, and an as_of date. It returns one
number between zero and one. The models are intended to provide a
calibrated prior when current evidence is sparse, a market does
not exist, or a forecaster needs a consistent place to begin.
This is deliberately narrower than a general forecasting agent. There is no retrieval layer, news feed, market price, or generated explanation. The release isolates a single capability so that the effect of model scale can be measured cleanly.
Input
- Question
- Resolution criteria
- Resolution date
- As-of date
Output
0.73 estimated probabilityExperiment
One variable: model size
The 1.7B, 4B, and 8B models share the same corpus, targets, seed, learning rate, and evaluation footing.
Holding those choices fixed turns the family into a controlled experiment. The central question is not simply whether a larger model scores better. It is which part of forecast quality changes as capacity increases.
Calibration stayed flat. Resolution did not.
All three models learn when to be cautious. The smallest model is worse at separating easier questions from harder ones. In Murphy terms, its loss is in resolution rather than calibration.
The 4B and 8B results are statistically indistinguishable. The 1.7B trails the 4B by 0.0119 Brier, with a paired 95% interval of +0.0080 to +0.0158.
| Model | Dev Brier | Calibration | Resolution |
|---|---|---|---|
| Tarot-Draw 8B | 0.1674 | 0.0010 | 0.0718 |
| Tarot-Draw 4B Recommended | 0.1684 | 0.0007 | 0.0708 |
| Tarot-Draw 1.7B | 0.1803 | 0.0004 | 0.0593 |
Question-level intervals do not include run-to-run training variance. Differences below roughly 0.008 Brier should be treated as unresolved.
The family
Choosing a model
Start with the 4B. It matches the 8B within the resolution of this experiment and requires a smaller deployment footprint.
The other sizes remain useful when hardware is the binding constraint or when reproducing the scaling comparison matters more than choosing a default.
Evidence
A result you can inspect
The forecasts, split metadata, metric code, and verification script ship with each release.
The published forward split contains 277 questions that resolved after a freeze date committed in public before it passed. The 4B scored 0.1831 Brier, the 8B scored 0.1893, and the 1.7B scored 0.2030. These are clean point estimates, but the split is too small to support a ranking between the 4B and 8B.
Confidence intervals use 10,000 paired, question-clustered bootstrap samples. Recomputing every headline number requires no model, GPU, or network access.
Verify the published results
uv run python verify.py
Limits
Where the prior stops
Tarot-Draw is a starting estimate, not an oracle. Its calibration should be measured again when the venue or question distribution changes.
-
Current information is absent.
The models cannot see breaking news, private evidence, or live market prices. A forecast that depends on them needs an external update.
-
Mechanical questions remain difficult.
Thresholds, counts, scores, and questions requiring precise arithmetic sit outside the strengths of a judgment prior.
-
Very short horizons are weak.
At horizons under seven days, the tested small model does not beat a market crowd at any point in a question's life.
-
Some domains are underrepresented.
Sports and obscure local elections are measured weaknesses in the present release.
Release
Models, code, and terms
Adapter weights, forecasts, and evaluation metadata are released under CC BY-NC 4.0. Verification and inference code are Apache 2.0. The training corpus is documented, not redistributed.
- Version
- 1.0
- Published
- 29 August 2026
- Authors
- Arya Somu; Bruce Nshuti Hirwa
- Publisher
- Laplace Research
Cite this release
@misc{somu2026tarotdraw,
title = {Tarot-Draw},
author = {Somu, Arya and Hirwa, Bruce Nshuti},
year = {2026},
publisher = {Laplace Research},
url = {https://laplaceresearch.org/tarot-draw/}
}