Trust & transparency

Data Sources & Methodology

Tavalyze is currently a 100-player MVP spanning five major European leagues. This page explains what is verified, what comes from another provider and what exists only to demonstrate the future product.

Verified

A fact checked against an official club, league or governing-body announcement. A direct source link and check date should be shown.

Sourced estimate

An estimate published by a named third-party data provider. Market value is an opinion, not the same as a transfer fee.

Demo data

Temporary information used to build and test the product. It must not be presented as current or authoritative.

Modelled

A Tavalyze output calculated from documented inputs and assumptions. It is a scenario—not a confirmed future event.

What the current MVP does

  • Player and team facts: new league snapshots show a named source and check date. Profiles without those links remain prototype data and should not be treated as current or authoritative.
  • Market values: the expanded dataset uses dated Transfermarkt league snapshots. These are third-party estimates and never the same thing as a confirmed transfer fee.
  • Value forecasts: a simple age-based demo model with base, upside and downside scenarios.
  • Club Fit: a prototype score using position, age, estimated value and manually defined club profiles. It does not use live rumors or verified squad needs.

Path to real predictions

  1. 1. Connect licensed football and contract data.
  2. 2. Store source, timestamp and confidence per field.
  3. 3. Train and back-test models on historical transfers.
  4. 4. Publish accuracy and calibration results.

Real-data connection

API-Football adapter ready

Tavalyze now has a server-only connection layer for player profiles, statistics, squads and transfers. The secret key is never sent to the browser.

  1. 1. Create a free API-Football account.
  2. 2. Copy .env.example to .env.local.
  3. 3. Add the key as API_FOOTBALL_KEY and restart the development server.
  4. 4. Open /api/football/status to verify the connection.
Get API accessOfficial documentation

Test the live connection

Search the API-Football player database. These profile facts come from the connected provider; market values still use Tavalyze's separately labelled estimates.

One submitted search may use one of the 100 daily API requests.

Explore player data