Terms of Service

1. Acceptance of Terms

By accessing and using TrueElo at trueelo.app ("the Service"), you accept and agree to be bound by these Terms of Service. If you do not agree to these terms, please do not use the Service.

2. Description of Service

TrueElo is a chess analysis tool that provides position evaluation and practical win rate analysis. The Service combines engine analysis with statistical data from public chess databases to help players make better decisions. The Service is currently provided free of charge; paid features, if introduced, will be described in these Terms before they are offered.

3. No Professional Chess Advice

Important: TrueElo is an educational and informational tool only. It is not professional chess coaching, training, or advice. Analysis results, win rates, and move recommendations are statistical estimates based on historical game data and engine calculations.

You should not rely solely on TrueElo for:

• Tournament preparation on its own
• Professional or competitive chess decisions
• Wagering or gambling on chess outcomes

4. User Obligations

You agree to:

• Use the Service for lawful purposes only
• Not attempt to disrupt, overload, or impair the Service
• Not use automated tools to access the Service in a manner that exceeds reasonable use
• Not attempt to reverse engineer, decompile, or extract source code from the Service
• Respect the intellectual property rights of third parties
• Comply with Lichess Terms of Service when using data derived from their API

5. Third-Party Services and Open Source

TrueElo integrates with third-party services and open-source software:

• Lichess: All chess game data is sourced from the Lichess Open Database (CC0/Public Domain license). TrueElo does not own this data. Lichess retains ownership of all game data. TrueElo provides only the statistical analysis of this public data. The data is also subject to Lichess Terms of Service. TrueElo also reads the games of a Chess.com account you link, through Chess.com’s public API only. Those games are Chess.com’s: they are analysed in your browser and never stored, and the connector is disabled rather than worked around should Chess.com object. We make no guarantees about the completeness, accuracy, or timeliness of this data.
• Stockfish Engine: TrueElo uses the Stockfish chess engine, licensed under the GNU General Public License v3. We do not claim ownership of Stockfish.

We are not responsible for the availability, accuracy, or functionality of third-party services. Changes to these services may affect the Service without notice.

6. User-Generated Content

Content you create (repertoire lines, drill progress, settings) is stored privately under your account, so it is there on every device you sign in to. You retain full ownership. Only your account can read it, and we do not sell it, share it, or use it to train anything.

Export and Import in Settings let you take your data out as a file and bring it back at any time.

7. Data Storage and Loss

Your saved work is stored under your account with Google Firebase, and a copy is cached on each device you sign in to, so your work is readable offline. Signing in on a new device brings it with you; clearing one browser does not remove it from your account. Changes you make while offline are saved on your device and reach your account when you are back online.

Warning: Deleting your data in Settings removes it from your account and cannot be undone. Use the export feature in Settings to keep a backup first.

We are not responsible for data loss due to:

• Deletion you carry out yourself
• Service disruptions or technical issues
• User error or accidental deletion

8. Intellectual Property

The TrueElo user interface, design, branding, statistical analysis methodology, and original code are the property of the Service operator.

Important: TrueElo does NOT own the underlying chess game data. All game data is owned by Lichess.org and released under CC0 (Public Domain). TrueElo owns only the original statistical analysis and derived calculations.

Third-party components retain their original licenses: Stockfish (GPL v3), Lichess data (CC0). You may not copy, modify, distribute, or create derivative works of the TrueElo interface without permission.

9. Accuracy Disclaimer

Win rates, evaluations, and move recommendations provided by TrueElo are statistical estimates, not guarantees of game outcomes. Accuracy may vary based on:

• Available sample size for a given position
• Selected analysis parameters
• Position complexity
• Changes in playing styles over time

Historical win rates do not predict future outcomes. Chess is a complex game where skill, psychology, and specific circumstances affect results.

10. Disclaimer of Warranties

THE SERVICE IS PROVIDED "AS IS" AND "AS AVAILABLE" WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.

We do not warrant that:

• The Service will be uninterrupted, timely, secure, or error-free
• Analysis results will be accurate, complete, or reliable
• Any errors in the Service will be corrected
• The Service will meet your specific requirements

11. Limitation of Liability

TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, IN NO EVENT SHALL THE SERVICE OPERATOR, ITS AFFILIATES, OR LICENSORS BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, PUNITIVE, OR EXEMPLARY DAMAGES, INCLUDING BUT NOT LIMITED TO:

• Loss of profits, revenue, or data
• Loss of use or goodwill
• Business interruption
• Chess game losses or rating changes
• Costs of substitute services

This limitation applies regardless of the legal theory (contract, tort, or otherwise) and even if we have been advised of the possibility of such damages.

12. Indemnification

You agree to indemnify and hold harmless the Service operator from any claims, damages, losses, or expenses (including reasonable attorneys' fees) arising from your use of the Service or violation of these Terms.

13. Modifications to Service and Terms

We may change, pause, or withdraw the Service, or any part of it, at any time and without notice. We may also update these Terms of Service from time to time. The "Last updated" date at the top of this page indicates when these Terms were last revised.

If you keep using the Service after a change, you accept the revised Terms.

14. Termination

We may terminate or restrict your access to the Service at any time, without notice, for conduct that we believe violates these Terms, is harmful to other users or the Service, or for any other reason at our sole discretion.

Upon termination, your right to use the Service ceases immediately. Provisions that by their nature should survive termination (including disclaimers, limitations of liability, and indemnification) will remain in effect.

15. Governing Law and Disputes

These Terms shall be governed by and construed in accordance with applicable laws, without regard to conflict of law principles. Any disputes arising from these Terms or the Service shall be resolved through good-faith negotiation. If negotiation fails, disputes shall be submitted to binding arbitration or small claims court at the operator's discretion.

16. Severability

If any provision of these Terms is found to be unenforceable or invalid, that provision shall be limited or eliminated to the minimum extent necessary, and the remaining provisions shall remain in full force and effect.

17. Entire Agreement

These Terms, together with our Privacy Policy and Cookie Policy, constitute the entire agreement between you and the Service operator regarding your use of the Service.

18. Contact

For questions about these Terms of Service, please contact us.