Legal

Terms

Effective 6 August 2026

Beta service

Blunderproof is a beta chess-learning service. Features, evidence models, stored formats, and availability may change. Keep an export of anything you cannot afford to lose. The service is provided without a promise of uninterrupted availability or a particular chess-rating improvement.

Your responsibilities

Use only accounts and data you are entitled to inspect. Do not attack, scrape at abusive volume, evade limits, upload malicious material, or use the service to assist live play where outside help is prohibited. Follow the rules of Chess.com, Lichess, and any event in which you participate.

Advice and measurement

Engine evaluations and coaching estimates are educational aids, not guarantees. Confidence reflects the amount and diversity of evidence available. A label about a chess pattern is not a judgment about the person using the product.

Accounts and deletion

You are responsible for securing your sign-in session. You may export or permanently delete the account from Profile. We may suspend abusive use or discontinue the beta, subject to applicable law and any notice commitments published for the beta cohort.

Operator details

Blunderproof is operated by Petr Lupínek. Contact: lupinekxbt@gmail.com. A service address will be published here before the public launch; until then this build is offered as an invite-only beta.

Read the Privacy notice for data handling.