Privacy Policy

Last updated: 8 March 2026

1. Data Controller

Chess Fair Play Analyzer ("we", "us", "the Service") is operated from the United Kingdom. We are the data controller for the personal data processed through this Service, within the meaning of the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018.

2. What Data We Collect

2.1 Data you provide:

Chess.com usernames entered for analysis.

2.2 Data retrieved from third parties:

Publicly available game data (PGNs, ratings, results) from the Chess.com public API for the username provided.

2.3 Data generated by the Service:

Engine analysis results, computed statistical features, and the classification verdict.

2.4 Data collected automatically:

Standard server logs (IP address, browser user agent, timestamps, pages visited).
Device and browser information: CPU core count, device memory, GPU model (via WebGL), screen resolution, device pixel ratio, touch capability, browser name, operating system, timezone, and language settings.
A hashed device identifier generated from the hardware and browser properties listed above, used to distinguish unique visitors and understand usage patterns. This is not a cookie and does not persist across browser changes.
Usage analytics: analysis start/completion events, per-stage timing, error events, and whether an analysis was abandoned before completion.
Cookies and similar technologies used by third-party advertising partners (see Section 6).

3. How We Use Your Data

We use the data collected for the following purposes:

To provide the analysis service you request.
To store analysis results for our internal records and model improvement.
To understand usage patterns, measure performance, and count unique visitors via the hashed device identifier.
To maintain and improve the Service.
To serve advertisements via third-party ad networks.

4. Legal Basis for Processing

Under the UK GDPR, we process personal data on the following legal bases:

Legitimate interest (Article 6(1)(f)) — to provide the Service, analyse publicly available game data, store results, and improve our models.
Consent (Article 6(1)(a)) — for the placement of non-essential cookies by third-party advertising partners. You may withdraw consent at any time.

5. Data Retention

Analysis results and associated data (PGNs, features, verdicts) are retained indefinitely for internal use and model improvement.
Server logs are retained for up to 12 months.
You may request deletion of data associated with a specific username by contacting us (see Section 10).

6. Cookies and Advertising

This Service uses cookies:

Essential cookies: Required for the Service to function. No consent needed under the Privacy and Electronic Communications Regulations 2003 (PECR).
Advertising cookies: Third-party ad networks may place cookies to serve personalised advertisements. These are set only with your consent, in accordance with PECR and the UK GDPR. You can manage your cookie preferences at any time.

Third-party advertising partners may collect and process data in accordance with their own privacy policies. We recommend reviewing those policies.

7. Data Sharing

We do not sell your personal data. We may share data with:

Third-party advertising networks (aggregated or cookie-based data, with your consent).
Service providers who assist with hosting and infrastructure.
Law enforcement or regulatory authorities, if required by law.

8. International Transfers

Some third-party services (such as ad networks or hosting providers) may process data outside the United Kingdom. Where this occurs, we ensure appropriate safeguards are in place in accordance with UK GDPR requirements, such as Standard Contractual Clauses or adequacy decisions.

9. Your Rights

Under the UK GDPR, you have the right to:

Access — request a copy of the personal data we hold about you.
Rectification — request correction of inaccurate data.
Erasure — request deletion of your data ("right to be forgotten").
Restriction — request that we limit processing of your data.
Portability — receive your data in a structured, machine-readable format.
Object — object to processing based on legitimate interests.
Withdraw consent — where processing is based on consent, you may withdraw it at any time.

To exercise any of these rights, please contact us using the details in Section 10. We will respond within one month.

10. Contact

For privacy-related enquiries or to exercise your rights, please contact us at [email protected].

11. Complaints

If you are unsatisfied with how we handle your data, you have the right to lodge a complaint with the Information Commissioner's Office (ICO):

Website: ico.org.uk
Phone: 0303 123 1113

12. Changes to This Policy

We may update this Privacy Policy from time to time. Changes take effect upon posting. We encourage you to review this page periodically.