The ledger

Verify it yourself

The raw files are served unmodified and the repository is public. Nothing here asks you to take our word for anything.

What this proves, and what it does not

Each layer below has a deliberately narrow claim, and the narrowness is the point. A proof that is described as stronger than it is does more damage than no proof at all.

Recomputing the chain

Clone the repository and run one command. It reads every file in predictions/, recomputes each SHA-256 over the entry with its own hash field removed, and checks that each entry's prev_hash matches the one before.

git clone https://github.com/GitSimaao/proofodds
cd proofodds
python -m proofodds.verify

Or point it at a directory of files downloaded from this site. It ignores anything in there that is not a ledger entry — the build summary at /predictions/_chain.json among them — and reports only on the chain itself.

python proofodds/verify.py /path/to/downloaded/predictions

Recomputing the score

The command above proves nothing here was altered. It says nothing about whether the number on the scorecard is the right number for these files, so there is a second command for that half. It reads the sealed entries, joins them to the raw results, and recomputes the de-vigging, the log loss and the interval in a separate implementation from the one that publishes them — then fails if the two disagree. --csv writes one row per graded match, so the whole scorecard fits in a spreadsheet column.

pip install -r requirements.txt
python scripts/rescore.py --refresh --csv audit.csv

Verifying an external timestamp

For any row with a proof, download the JSON and its matching .ots file into the same directory. Compare the SHA-256 shown by ots info with the JSON, then use ots verify for full verification against Bitcoin. That last step requires access to a Bitcoin Core node. A block number on this page means the matching proof contains that attestation; it does not claim this web server independently verified the Bitcoin chain.

pip install opentimestamps-client
curl -O https://proofodds.com/predictions/YYYY-MM-DD.json
curl -o YYYY-MM-DD.json.ots https://proofodds.com/timestamps/YYYY-MM-DD.json.ots
sha256sum YYYY-MM-DD.json
ots info YYYY-MM-DD.json.ots
ots verify YYYY-MM-DD.json.ots