Privacy Policy

Who is responsible for processing your data?

David Menéndez Rujas (hereinafter "CHESS STALKER"), Spanish National ID 71771512N, Calle Concejo de Ibias 1, 2ºT, CP 33204, Gijón, Spain. Contact: info@chessstalker.com.

Information that CHESS STALKER collects

Identification dataName, and profile picture only if you sign in with Google.

Contact dataEmail address.

Payment methodPayment method used for managing payments or charges (handled by Paddle; CHESS STALKER does not store card numbers).

Content you saveyour Studio studies (positions, lines, notes and titles) and the panels you add. They are private: only you can see them, they are neither read nor used for any purpose other than showing them to you, and they are deleted with your account.

Technical dataIP address, browser and technical error traces, solely for security and fault diagnosis.

Why is CHESS STALKER authorised to process your data?

Your personal data is securely stored and processed in accordance with the GDPR (Regulation EU 2016/679).

PurposeLegal basis

User registration and account creation.Consent and pre-contractual measures (Art. 6(1)(b) GDPR).

Provision of Platform services.Contractual measures (Art. 6(1)(b) GDPR).

Responding to requests, incidents or queries.Contractual measures (Art. 6(1)(b) GDPR).

Security, fault diagnosis and abuse prevention.Legitimate interest (Art. 6(1)(f) GDPR).

Cookie-free audience analytics.Legitimate interest (Art. 6(1)(f) GDPR), with the option to object in the cookie banner.

Statistics about players from public sources (section 4).Legitimate interest (Art. 6(1)(f) GDPR).

The User may withdraw consent at any time by emailing info@chessstalker.com.

Player data from public sources

CHESS STALKER builds statistics about chess players from information that is already public: the official FIDE rating lists (name, federation, title, year of birth and rating), games published in public bulletins and databases, and the public profiles and games of Chess.com and Lichess, retrieved through their public APIs. No contact data or special categories of data are processed.

The purpose is the statistical analysis of public chess activity, and the legal basis is the legitimate interest (Art. 6(1)(f) GDPR) of CHESS STALKER and its Users in studying the game, balanced against the public and sporting nature of the information. The data is refreshed with each monthly FIDE list and kept for as long as it remains public at its source.

What a player profile includes. Based on their public games, the profile shows playing statistics: opening repertoire, results, engine-computed accuracy and mistakes, performance by time control, and a practice bot (Twin Bot) that plays their openings at a level similar to their rating. This is an automated analysis of their sporting performance for game preparation; no decision with legal effects on them is taken from it. Profiles may appear in search engines.

Minors. Profiles of players under 18 without a FIDE title are not indexed by search engines, do not show the year of birth, and their practice bot does not carry their name. Parents or guardians can ask for the profile to be hidden by writing to privacy@chessstalker.com.

If you are a player and wish to object to this processing or have your profile hidden, write to privacy@chessstalker.com with your name and your FIDE ID or username; we will handle the request within one month.

Data retention

Personal data is retained while you keep your account and for the purposes for which it was provided. The User may delete their account at any time from the "My account" section of the application: deletion is immediate, your email and your studies are erased and your survey answers are unlinked. Three exceptions: encrypted backups, kept for up to 28 days plus one monthly archive copy for 12 months, which are never restored except after a serious incident; Paddle transaction references, without identifying data, to handle claims and refunds; and invoices, which Paddle keeps as merchant of record under a legal obligation. Technical security and diagnostic data is kept for a limited period, never exceeding 12 months.

Users' rights

Users have the right to: access, rectify, erase, restrict processing, object, port their data and not be subject to automated decisions. Contact privacy@chessstalker.com. The right to erasure can also be exercised directly from "My account" in the application.

Supervisory authority

You may lodge a complaint with the Spanish Data Protection Agency (AEPD): 900 293 183; C/Jorge Juan 6, 28001 Madrid; https://sedeagpd.gob.es.

Data security

CHESS STALKER has established all available technical means to prevent loss, misuse, alteration, unauthorised access or theft of User data.

Transfers to third parties

Personal data will not be disclosed to third parties without prior User consent, unless necessary for processing purposes. To provide the service, CHESS STALKER relies on the following data processors:

ProcessorServiceLocation

Paddle.com Market LtdPayment and subscription management (merchant of record that issues the charge)United Kingdom / USA

Google Firebase (Google Ireland Ltd)Account authentication and sign-inEU / USA

Hetzner Online GmbHServer and database hostingGermany (EU)

Sentry (Functional Software, Inc.)Technical error diagnosis: IP, browser and error trace, only when a failure occursEU (Germany); US-based company

UmamiAnonymised audience analytics, self-hosted on our own serversGermany (EU)

International transfers to providers outside the European Economic Area are carried out with the safeguards provided for in the GDPR (adequacy decisions, the EU-US Data Privacy Framework or Standard Contractual Clauses approved by the European Commission).

In addition, when you look up a Chess.com or Lichess player, your browser connects directly to the public APIs of those platforms, which receive your IP address under their own privacy policies. CHESS STALKER sends them no other data about you.

Questions

Contact privacy@chessstalker.com for any questions about our Privacy Policy.

Última actualización / Last updated: October 2026